alibi: [18] In Latin, alibi means literally ‘somewhere else’. It is the locative form (that is, the form expressing place) of the pronoun alius ‘other’ (which is related to Greek allos ‘other’ and English else). When first introduced into English it was used in legal contexts as an adverb, meaning, as in Latin, ‘elsewhere’: ‘The prisoner had little to say in his defence; he endeavoured to prove himself Alibi’, John Arbuthnot, Law is a bottomless pit 1727.
But by the end of the 18th century it had become a noun, ‘plea of being elsewhere at the time of a crime’. The more general sense of an ‘excuse’ developed in the 20th century. Another legal offspring of Latin alius is alias. This was a direct 16th-century borrowing of Latin aliās, a form of alius meaning ‘otherwise’. => alias, else
alibi (n.)
1743, "the plea of having been elsewhere when an action took place," from Latin alibi "elsewhere, somewhere else," locative of alius "(an)other" (see alias (adv.)). The weakened sense of "excuse" is attested since 1912, but technically any proof of innocence that doesn't involve being "elsewhere" is an excuse, not an alibi.
例文
1. This argument is only too blatantly an alibi for domestic repression.
という言い訳は、完全に国内の弾圧活動から解放されている。
2.Mick had an airtight alibi .
ミックには確かなアリバイがある。
3.He has a solid alibi .
彼にはアリバイの確証がある。
4.The police verified that she had an airtight alibi .
警察は彼女が犯罪現場にいない証拠を持っていることを明らかにした。
5.Do you have any proof to substantiate your alibi ？