buttress (n.) Look up buttress at Dictionary.com
early 14c., from Old French (arc) botrez "flying buttress," apparently from bouter "to thrust against," of Frankish origin (compare Old Norse bauta "to strike, beat"), from Proto-Germanic *butan, from PIE root *bhau- "to strike" (see butt (v.)).
buttress (v.) Look up buttress at Dictionary.com
late 14c., literal and figurative, from buttress (n.). Related: Buttressed; buttressing.