attacked

backed

backpacked

backtracked

barebacked

barracked

bivouacked

blacked

blackjacked

bushwhacked

carjacked

clacked

counterattacked

cracked

crookbacked

flacked

fracked

gobsmacked

hacked

highjacked

hijacked

humpbacked

hydrocracked

jacked

knacked

knapsacked

lacked

medevacked

medivacked

mossbacked

overpacked

packed

paperbacked

pickabacked

piggybacked

prepacked

quacked

quarterbacked

racked

ransacked

reattacked

repacked

reracked

restacked

retacked

retracked

sacked

shacked

shellacked

sidetracked