Birdie

A golf score of one stroke under par for a hole. For example, scoring a 3 on a par-4 hole or a 2 on a par-3 hole constitutes a birdie.

American slang from the early 1900s, when 'bird' meant something excellent or first-rate. The golf term was coined around 1903 at Atlantic City Country Club, with 'eagle' and 'albatross' following the bird theme.