(idiomatic) As hard as a bone, rock hard.

Alternative spelling of diehard

Alternative spelling of diehard

(economics) Money backed by specie and easily convertible into foreign currencies. / (US, politics) Money contributed directly to a candidate rather than to a party or committee.

(slang) A tough person. / (New Zealand, slang) An amusing, funny, witty, or possibly strange person. May be used as a term of endearment.

A type of pronunciation change required when speaking certain Celtic languages.

(of a living being) To die only after a desperate struggle for life. / (of a custom, idea etc) To be slow in changing or disappearing.

Alternative form of hardworking

(astronautics) An explosion in a rocket engine during startup, usually due to the presence of too much propellant prior to ignition.

A technical skill, not one that is interpersonal.