The UPSC CDS 1 2026 exam isn’t just about how many hours you pull at your desk; it’s about studying smart. When you’re sitting in that exam hall facing 120 English questions, your vocabulary is either going to be your best friend or your worst enemy.
UPSC has a habit of picking words for the CDS 1 2026 Exam that sound simple but have tricky nuances. If you’re guessing between two options because a word "looks familiar," you’re already losing ground.
We have put together this list of 25 must-know vocab words to take the guesswork out of your prep. We’ve kept it simple: you get the Hindi meaning to make it stick, four synonyms and antonyms for depth, and a quick practice set to see where you actually stand.
Stop scrolling through random word lists and start mastering the ones that actually show up on the paper.
25 High-Frequency Words You Can't Ignore for CDS 1 2026 Exam
1. Word: Abate (कम करना / धीमा होना)
Meaning: To become less intense, active, or widespread.
Synonyms: Subside, Moderate, Decrease, Ebb
Antonyms: Intensify, Increase, Escalate, Amplify
2. Word: Alacrity (तत्परता / उत्साह)
Meaning: Brisk and cheerful readiness to do something.
Synonyms: Eagerness, Zeal, Promptness, Readiness
Antonyms: Apathy, Lethargy, Reluctance, Indifference
3. Word: Ameliorate (सुधारना)
Meaning: To make something bad or unsatisfactory better.
Synonyms: Improve, Amend, Enhance, Upgrade
Antonyms: Worsen, Deteriorate, Aggravate, Exacerbate
4. Word: Arduous (कठिन / श्रमसाध्य)
Meaning: Involving or requiring strenuous effort; difficult and tiring.
Synonyms: Laborious, Strenuous, Onerous, Toilsome
Antonyms: Effortless, Easy, Simple, Facile
5. Word: Ascetic (तपस्वी / आत्मसंयमी)
Meaning: Characterized by severe self-discipline and abstention from all forms of indulgence.
Synonyms: Austere, Abstinent, Spartan, Hermitic
Antonyms: Hedonistic, Sybaritic, Self-indulgent, Extravagant
6. Word: Benevolent (परोपकारी / दयालु)
Meaning: Well-meaning and kindly; serving a charitable rather than a profit-making purpose.
Synonyms: Altruistic, Philanthropic, Benign, Generous
Antonyms: Malevolent, Miserly, Spiteful, Malicious
7. Word: Candid (स्पष्टवादी / निष्कपट)
Meaning: Truthful and straightforward; frank.
Synonyms: Forthright, Honest, Blunt, Ingenuous
Antonyms: Evasive, Deceptive, Guarded, Insincere
8. Word: Cogent (ठोस / प्रà¤ावशाली)
Meaning: (Of an argument or case) clear, logical, and convincing.
Synonyms: Persuasive, Compelling, Convincing, Lucid
Antonyms: Incoherent, Weak, Unconvincing, Flawed
9. Word: Complacent (आत्मसंतुष्ट)
Meaning: Showing smug or uncritical satisfaction with oneself or one's achievements.
Synonyms: Smug, Self-satisfied, Contented, Gloating
Antonyms: Humble, Modest, Dissatisfied, Discontent
10. Word: Deference (सम्मान / लिहाज)
Meaning: Polite submission and respect.
Synonyms: Reverence, Homage, Respect, Regard
Antonyms: Contempt, Disrespect, Defiance, Disdain
11. Word: Diligent (परिश्रमी / मेहनती)
Meaning: Having or showing care and conscientiousness in one's work or duties.
Synonyms: Industrious, Assiduous, Sedulous, Hard-working
Antonyms: Lazy, Indolent, Idle, Slothful
12. Word: Disdain (तिरस्कार / घृणा)
Meaning: The feeling that someone or something is unworthy of one's consideration or respect.
Synonyms: Contempt, Scorn, Derision, Condescension
Antonyms: Admiration, Esteem, Respect, Approval
13. Word: Effrontery (धृष्टता / गुस्ताखी)
Meaning: Insolent or impertinent behavior.
Synonyms: Audacity, Impudence, Cheek, Temerity
Antonyms: Timidity, Modesty, Politeness, Shyness
14. Word: Eloquent (सुवक्ता / वाकपटु)
Meaning: Fluent or persuasive in speaking or writing.
Synonyms: Articulate, Silver-tongued, Fluent, Expressive
Antonyms: Inarticulate, Mumbled, Hesitant, Dull
15. Word: Ephemeral (अल्पकालिक / क्षणà¤ंगुर)
Meaning: Lasting for a very short time.
Synonyms: Transitory, Fleeting, Brief, Evanescent
Antonyms: Permanent, Eternal, Perennial, Lasting
16. Word: Equanimity (धीरज / मानसिक संतुलन)
Meaning: Mental calmness, composure, and evenness of temper, especially in a difficult situation.
Synonyms: Serenity, Composure, Placidity, Poise
Antonyms: Agitation, Anxiety, Panic, Perturbation
17. Word: Erudite (विद्वान / ज्ञानी)
Meaning: Having or showing great knowledge or learning.
Synonyms: Scholarly, Learned, Knowledgeable, Academic
Antonyms: Ignorant, Uneducated, Illiterate, Uninformed
18. Word: Fastidious (नकचढ़ा / अति-सावधान)
Meaning: Very attentive to and concerned about accuracy and detail.
Synonyms: Meticulous, Scrupulous, Punctilious, Choosy
Antonyms: Careless, Lax, Negligent, Indiscriminate
19. Word: Frugal (मितव्ययी / कंजूस)
Meaning: Sparing or economical with regard to money or food.
Synonyms: Thrifty, Economical, Parsimonious, Provident
Antonyms: Extravagant, Wasteful, Lavish, Prodigal
20. Word: Gregarious (मिलनसार)
Meaning: (Of a person) fond of company; sociable.
Synonyms: Convivial, Outgoing, Social, Affable
Antonyms: Reclusive, Introverted, Unsociable, Hermitic
21. Word: Innocuous (अहानिकर / सीधा-सादा)
Meaning: Not harmful or offensive.
Synonyms: Harmless, Safe, Benign, Inoffensive
Antonyms: Toxic, Dangerous, Harmful, Noxious
22. Word: Lethargic (सुस्त / आलसी)
Meaning: Affected by lethargy; sluggish and apathetic.
Synonyms: Sluggish, Torpid, Listless, Enervated
Antonyms: Energetic, Vibrant, Active, Animated
23. Word: Obscure (अस्पष्ट / अनजान)
Meaning: Not discovered or known about; uncertain.
Synonyms: Vague, Ambiguous, Opaque, Recondite
Antonyms: Clear, Obvious, Famous, Explicit
24. Word: Prudent (विवेकपूर्ण / चतुर)
Meaning: Acting with or showing care and thought for the future.
Synonyms: Sensible, Wise, Cautious, Judicious
Antonyms: Reckless, Careless, Rash, Impudent
25. Word: Ubiquitous (सर्वव्यापी)
Meaning: Present, appearing, or found everywhere.
Synonyms: Pervasive, Omnipresent, Universal, Widespread
Antonyms: Rare, Scarce, Uncommon, Infrequent
CDS Style Vocabulary Practice Set (with Solutions)
Directions: Each of the following sentences has a blank space and four words are given below it. Select the word you consider most appropriate for the blank space.
1. Even during the heat of the battle, the Captain displayed remarkable __________, guiding his troops with a calm mind.
(a) Effrontery
(b) Equanimity
(c) Alacrity
(d) Lethargy
Correct Answer: (b) Equanimity
Explanation: In a battle, a leader needs "mental calmness" or composure. Equanimity fits perfectly. Effrontery (insolence) or Lethargy (laziness) would be negative in this context.
2. The report provided a __________ argument for the modernization of the Indian Navy’s fleet.
(a) Obscure
(b) Ephemeral
(c) Cogent
(d) Innocuous
Correct Answer: (c) Cogent
Explanation: An argument for a policy change needs to be "clear, logical, and convincing." Cogent is the correct term. Obscure means unclear, which would not help an argument.
3. A soldier must be __________ in his duties, as even a small mistake can lead to a major security breach.
(a) Fastidious
(b) Complacent
(c) Gregarious
(d) Frugal
Correct Answer: (a) Fastidious
Explanation: Since even a "small mistake" matters, the soldier must be "very attentive to detail/accuracy." Fastidious is the right choice. Being Complacent (self-satisfied/careless) would cause the breach.
4. The effects of the minor skirmish were __________, and peace was restored within a few hours.
(a) Arduous
(b) Ephemeral
(c) Erudite
(d) Ubiquitous
Correct Answer: (b) Ephemeral
Explanation: The sentence mentions peace was restored "within a few hours," meaning the effects lasted for a "very short time." Ephemeral means short-lived.
5. The government is trying to __________ the living conditions of the villagers in the border areas.
(a) Abate
(b) Ameliorate
(c) Disdain
(d) Obscure
Correct Answer: (b) Ameliorate
Explanation: To "make better" or improve living conditions is to Ameliorate. Abate (to reduce) is usually used for something negative like a storm or a nuisance.
Directions: Select the word that is most nearly OPPOSITE (Antonym) in meaning to the underlined word.
1. The officer was known for his Prudent decisions during the rescue mission.
(a) Sensible
(b) Judicious
(c) Reckless
(d) Cautious
Correct Answer: (c) Reckless
Explanation: Prudent means acting with care and thought for the future. Its direct opposite is Reckless (acting without thinking of consequences).
2. He is quite Gregarious and enjoys the company of his fellow cadets.
(a) Convivial
(b) Introverted
(c) Sociable
(d) Affable
Correct Answer: (b) Introverted
Explanation: Gregarious means fond of company or sociable. The opposite is Introverted (shy or keeping to oneself). Options (a), (c), and (d) are all synonyms
Clearing the CDS 1 2026 exam isn’t about memorizing the entire dictionary in one night. It’s about mastering these high-frequency words so thoroughly that they become second nature to you.
Whether you’re analyzing a passage or tackling the Synonyms section, this vocabulary will give you the edge you need to stay ahead of the curve.
Take these 25 words, use them in your daily conversations, and keep revisiting the practice set until you’re hitting 100% accuracy. The path to the Academy is built on these small, disciplined steps.
