"a vain, shallow fellow, a fop," 1570s, from cokkes comb (1560s, see cockscomb), the name of a device worn in the cap by licensed fools. Johnson has coxcomical (adj.) "foppish, conceited," but discourages it as "a low word unworthy of use."
cowrie
cowslip
Cox
coxa
coxal
coxcomb
coxswain
coy
coyote
coz
coze