(transport) A collision where the front ends of two vehicles (such as ships, trains, cars, planes, etc.) hit each other, as opposed to a side-collision or rear-end collision.

The chief public representative of a nation having duties, privileges and responsibilities varying greatly depending on the constitutional rules; a monarch in a monarchy, and often styled president in a republic, but variations such as collegiality exist.

Used other than figuratively or idiomatically: see cylinder, head.

(intransitive, idiomatic, slang, vulgar) To perform oral sex on another person.

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.

present participle of head-butt

(idiomatic) To argue uncompromisingly. / To struggle against something that does not give way.

(idiomatic) Used as an informal warning, caution, or call for attention; pay attention!

Alternative spelling of heads-up

(poker) Containing only two players.