1838, earlier cater-cornered (1835, American English), from now-obsolete cater "to set, cut, or move diagonally" (1570s), from Middle French catre "four," from Latin quattuor (from PIE root *kwetwer- "four"). Compare carrefour.
catsup
cattail
cattish
cattle
catty
catty-cornered
catwalk
Caucasian
Caucasoid
Caucasus
caucus