/od"bawl'/ , Informal.
n.
1. a person or thing that is atypical, bizarre, eccentric, or nonconforming, esp. one having beliefs that are unusual but harmless.
adj.
2. whimsically free-spirited; eccentric; atypical: an oddball scheme.
[ 1940-45, Amer.; ODD + BALL 1 ]