from Latinized form of Greek Kroisos, 6c. B.C.E. king of Lydia in Asia Minor, famously wealthy; hence, from late 14c., "rich man" or in other allusions to riches.
crock
crockery
crocket
crocodile
crocus
Croesus
croft
Crohn's disease
croissant
Cro-Magnon
cromlech