vagary

noun3

1. •
   An erratic, unpredictable occurrence or action.

   • This searching was facilitated by the author's knowledge of the vagaries of Anglo-Indian spelling and the numerous colonial-era transliteration systems used for loanwords from Indian languages. — 2018
2. •
   An impulsive or illogical desire; a caprice or whim.

   • And then came the day when my socialism grew respectable,—still a vagary of youth, it was held, but romantically respectable. — 1905
3. •
   Something vague.