(Britain) A girl chosen to lead a school's sixth form, whose duties may include representing the school and organising the prefects.

(informal) An experience or set of experiences which is intellectually challenging or stimulating.

With the head first or foremost.

(idiomatic, rare) Anything mindless; something that does not involve thinking.

plural of head rhyme

The use of alliteration at the beginning of stressed syllables

(idiomatic) A significant amount of energy, vigour or momentum, sufficient to make progress or succeed in a task.

(computing) A collision of the head of a hard drive with the platter, resulting in permanent damage to the hard drive.

(idiomatic) Incredibly; overwhelmingly.

(euphemistic) crazy, insane