say it: NAH-kowt
knockout is a noun and adjective meaning "a very attractive or seductive looking woman". It carries 3 recorded senses.
a blow that renders the opponent unconscious
Forms marked · are formed by the regular rule rather than recorded in the source data. English keeps a few hundred irregulars and the rest follow the pattern, so the rule is right far more often than not — but it is a rule, and the mark says so.
Definitions, synonyms and semantic relations for knockout come from Princeton University’s WordNet. The pronunciation comes from the CMU Pronouncing Dictionary. Commonness is measured against a corpus of everyday English. Full sources and licences.