The definition of crude is something rudimentary, undefined or undeveloped, or behavior that is impolite and improper.(adjective)
See crude in Webster's New World College Dictionary
Origin: ME < L crudus, bleeding, raw, rough < IE base *kreu-, congealed (blood) > raw, Gr kryos, frost & kreas, flesh, L crusta, cruor, MIr cru, blood
See crude in American Heritage Dictionary 4
crudeadjective cruder crud·er, crudest crud·est
Origin: Middle English, from Latin crūdus; see kreuə- in Indo-European roots.
Learn more about crude