I. noun 1. a claim or piece of evidence that one was elsewhere when an act, typically a criminal one, is alleged to have taken place • she has an alibi for the whole of yesterday evening.
‹informal› an excuse or pretext
• a catch-all alibi for failure and inadequacy.
II. verb — [with obj.] 1.
‹informal› provide an alibi for.
• her friend agreed to alibi her.
– origin late 17th cent. (as an adverb in the sense ‘elsewhere’): from Latin, ‘elsewhere’. The noun use dates from the late 18th cent. / usage: The word alibi, which in Latin means ‘elsewhere’, has been used since the 18th century to mean ‘an assertion by a person that he or she was elsewhere’. In the 20th century a new sense arose (originally in the US) with the meaning ‘an excuse’. This use is a fairly common and natural extension of the core meaning, but is still regarded as incorrect by some traditionalists.