What does cocksure mean?
Cocksure is an adjective describing someone who is completely — often excessively — certain of themselves or of the outcome of something. While simple confidence can be admirable, cocksure carries an unmistakably critical edge: it suggests assurance that outruns the evidence, a person who struts through life certain they are right when others can see they may not be. It appears most often in phrases like "cocksure attitude," "cocksure smile," or "too cocksure for his own good." The word dates from around the early sixteenth century, combining "cock," the strutting barnyard rooster long a symbol of aggressive self-display, with "sure." Writers and journalists reach for it when they want to puncture pomposity: the cocksure pundit whose predictions fail, the cocksure entrepreneur who ignores caution. Its usefulness lies precisely in that judgment built into the word — no one is ever described as cocksure approvingly. For anyone needing a single, pointed word for unwarranted self-belief, cocksure remains hard to beat.
adjectiveCompletely confident and certain, often to an excessive or presumptuous degree; arrogantly assured.
- Entirely confident or certain of something, often without adequate justification (e.g. 'cocksure of victory').
- Presumptuously or offensively self-assured in manner.
"He walked into the interview cocksure, never doubting for a moment that he would get the job."
"She was cocksure that the deal would close by Friday, despite every warning sign."
"The young lawyer's cocksure manner rubbed the senior partners the wrong way."
"Cock" here has nothing rude to do with it — it's the old English word for a strutting rooster, so calling someone cocksure literally paints them as a bird puffing its chest.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of cocksure
Cocksure arose in English in the early sixteenth century as a compound of "cock," referring to the rooster famed for its proud, strutting bearing, and "sure." The rooster had long been proverbial for swaggering self-confidence, which gave the compound its sense of presumptuous certainty. It shares its second element with the broader family of "sure" words such as assure, ensure, and insure, all ultimately from Latin securus via Old French sur.
How cocksure is actually used
Almost always carries a negative or critical connotation — it implies confidence beyond what is warranted. Common in both British and American English; register is neutral to slightly informal, acceptable in journalism and fiction.
Easily confused with cocksure
Not a real confusion; a more genuine near-form is "conceited," which means vainly preoccupied with oneself, whereas cocksure emphasizes overconfidence in one's judgments or outcomes.