add to
adulterate
affirm
animate
arm
armor
armor-plate
arouse
attest
augment
authenticate
back
back up
bank
barricade
bastardize
battle
bear out
beef up
blockade
bolster
boost
brace
brace up
brisk
brisken
buck up
bulwark
buoy
buttress
case harden
castellate
certify
cheer
chirk up
circumstantiate
confirm
contaminate
corroborate
corrupt
crenellate
cut
debase
denaturalize
denature
dig in
dilute
doctor
doctor up
fortified
add
alter
change
modify
forearm
re-arm
rearm
fortifies
fortifying
fort
fortification
fortress
mortify