cabbage (n.) Look up cabbage at Dictionary.com
type of cultivated culinary vegetable that grows a rounded head of thick leaves, mid-15c., caboge, from Old North French caboche "head" (in dialect, "cabbage"), from Old French caboce "head," a diminutive from Latin caput "head" (from PIE root *kaput- "head"). Earlier in Middle English as caboche (late 14c.). The plant was introduced to Canada 1541 by Jacques Cartier on his third voyage. First record of it in modern U.S. is 1660s.

The decline of "ch" to "j" in the unaccented final syllable parallels the common pronunciation of spinach, sandwich, Greenwich, etc. The comparison of a head of cabbage to the head of a person (usually disparaging to the latter) is at least as old as Old French cabus "(head of) cabbage; nitwit, blockhead," from Italian capocchia, diminutive of capo. The cabbage-butterfly (1816) is so called because its caterpillars feed on cabbages and other cruciferous plants.