An Aught

1. whit, the smallest part, iota.
2. (archaic) zero
3. The digit zero as the decade in years. For example, aught-nine for 1909 or 2009.

Usage notes

The use of aught and ought to mean "zero" is very much proscribed as the word aught originally meant the opposite of naught: "anything". This may be due to misanalysis, or may simply be the result of speakers confusing the meanings of aught and naught due to similar-sounding phonemes.