The term 'Ain't Alternative' is a phrase that has been used to describe something that is not an alternative option. It implies that there is no other choice or option available. The two crossword solutions for this term are 'ISNT' (4 letters) and 'ARENT' (5 letters). Both of these words are contractions of the phrase 'is not' and 'are not, ' respectively, which are used to express the idea that something is not an alternative.