crown / kroun/ • n. 1. a circular ornamental headdress worn by a monarch as a symbol of authority, usually made of or decorated with precious metals and jewels. ∎  (the Crown) the reigning monarch, representing a country's government. ∎  (usu. the Crown) the power or authority residing in the monarchy. ∎  an ornament, emblem, or badge shaped like a crown. ∎  a wreath of leaves or flowers, esp. that worn as an emblem of victory in ancient Greece or Rome. ∎  an award or distinction gained by a victory or achievement, esp. in sports: the world heavyweight crown.2. the top or highest part of something: the crown of the hill. ∎  the top part of a person's head or a hat. ∎  the part of a plant just above and below the ground from which the roots and shoots branch out. ∎  the upper branching or spreading part of a tree or other plant. ∎  the upper part of a cut gem, above the girdle. ∎  the part of a tooth projecting from the gum. ∎  an artificial replacement or covering for the upper part of a tooth. ∎  the point of an anchor at which the arms reach the shaft.3. (also crown piece) a British coin with a face value of five shillings or 25 pence, now minted only for commemorative purposes. ∎  a foreign coin with a name meaning ‘crown,’ esp. the krona or krone.4. (in full metric crown) a paper size, now standardized at 384 × 504 mm. ∎  (in full crown octavo) a book size, now standardized at 186 × 123 mm. ∎  (in full crown quarto) a book size, now standardized at 246 × 189 mm.• v. [tr.] 1. (usu. be crowned) ceremonially place a crown on the head of (someone) in order to invest them as a monarch. ∎  declare or acknowledge (someone) as the best, esp. at a sport: he was crowned world champion. ∎  (in checkers) promote (a piece) to king by placing another on top of it. ∎  rest on or form the top of: the distant knoll was crowned with trees. ∎  fit a crown to (a tooth). ∎ inf. hit on the head.2. be the triumphant culmination of (an effort or endeavor, esp. a prolonged one): years of struggle were crowned by a state visit to Paris.3. [intr.] (of a baby's head during labor) fully appear in the vaginal opening prior to emerging.PHRASES: crowning glory the best and most notable aspect of something.