Czech and Slovak (Kosák) : from a diminutive of Kos or
Kosa.
Slovenian (Košak) : nickname from a
simplified form of koščak, denoting a kind of nut tree
with very hard nuts, probably denoting a strong, vigorous man. Also
found as Koščak.
Join the Family
Your Partner in Parenting, From Baby Name Inspiration to College Planning.