amn't, aunt
It is not uncommon among older people or rural people (my grandmother used it) in the US to use 'a'nt' (pronounced with the short flat 'a' to rhyme with the usual US pronunciation of can't) not only for 'are not', but also for 'am not' and 'is not'. From this, I take it that 'a'nt' is a variant pronunciation of 'ain't', which is used for all numbers, persons and genders, mostly by the under-educated (schoolmarms used to go off the wall over 'ain't') but which is becoming more and more tolerated.

'Aunt' is generally pronounced the same way, with the short, flat 'a' sound, except that there are those who insist on the deep 'a' to rhyme with Brit pronunciation of 'can't'. This is thought by most USers to be hoity-toity, except, interestingly enough, among the black population where, in the black US usage, it is regularly prounced with the deep vowel sound.