(idiomatic) An advantage consisting in starting a competition or task earlier than might be expected; given (or taken), for example, prior to the beginning of a race.

The end of a mop, to which the thrums or rags are fastened. / (US) A clamp for holding the thrums or rags of a mop.

(idiomatic) To a considerable degree. / By force; violently.

In the United States, a government-funded preschool program for impoverished children.

present participle of head-butt

(informal) The person in charge; the highest-ranking person in an organization.

The hub of a propeller / The central part of a propeller, into which the blades fit

Having a bald head. / (nautical) (of a square-rigged ship) not having the royals set. / (nautical) (of a fore-and-aft rigged ship) having the topmasts struck down.

A screwdriver with a '+' shaped head for turning screws so socketed. / A screw turned by such a screwdriver.

(idiomatic) To rapidly reach a turning point or climax. / (idiomatic) To suddenly reveal that which has lain latent for a time.