damn / dam/ • v. [tr.] (in Christian belief) (of God) condemn (a person) to suffer eternal punishment in hell. ∎  (be damned) be doomed to misfortune or failure: the enterprise was damned. ∎  condemn, esp. by the public expression of disapproval. ∎  curse (someone or something).• interj. inf. expressing anger, surprise, or frustration: Damn! I forgot!• adj. inf. used for emphasis, esp. to express anger or frustration: turn that damn thing off! | don't be so damn silly! PHRASES: damn well inf. used to emphasize a statement, esp. when the speaker is angry: this is your mess and you can damn well clear it up!I'll be (or I'm) damned if inf. used to express a strong negative.not be worth a damn inf. have no value or validity at all.not give a damn see give.well I'll be (or I'm) damned inf. used as an expression of surprise.

damn in Christian belief, to be damned is to be condemned by God to suffer eternal punishment in hell. The word comes (in Middle English, via Old French) from Latin dam(p)nare ‘inflict loss on’, from damnum ‘loss, damage’.
damn with faint praise commend so feebly as to imply disapproval; from Pope's ‘An Epistle to Dr Arbuthnot’ (1735).

damn †condemn XIII; doom to eternal perdition XIV; (in imprecations) XVI. — (O)F. damner — L. damnāre orig. inflict loss upon, f. damnum loss, damage. Cf. CONDEMN.
Hence damn sb. the imprecation ‘damn!’ XVII. So damnable XIV (rare before XVI), damnation XIII. damnatory XVII. — L.

DAMN Chem. diaminomaleonitrile