buck·o 
(bŭkō)
(bŭkō)n. pl. buck·oes or buck·os
1. A blustering or bossy person.
2. Irish A young man; a lad.
[Alteration of BUCK1.]
- cosmogony
- cosmographer
- cosmographic
- cosmographical
- cosmographically
- cosmography
- cosmologic
- cosmological
- cosmological constant
- cosmologically
- cosmologist
- cosmology
- cosmonaut
- cosmopolis
- cosmopolitan
- cosmopolitanism
- cosmopolite
- cosmopolitism
- cosmos
- cosplay
- cosplayer
- cosponsor
- cosponsorship
- Cossack
- cosset