accelerate
accrue
accumulate
add to
advance
affirm
aggravate
animate
anneal
appreciate
attest
augment
authenticate
back
back up
balloon
be tough
bear out
beef up
bloat
blow up
bolster
boom
boost
brace
brace up
breed
broaden
buttress
case harden
certify
cheer
chirk up
circumstantiate
complicate
concentrate
condense
confirm
consolidate
corroborate
crescendo
deepen
develop
document
double
embolden
encourage
exercise
work out
strengthened
strengthening
strengthens
accessions
crystallisation
deformation
derangement
devaluation
enfeeblement
heighten
lessen
loosen
lower
nationalization
postponement
remodelling
rending
severance
soften
supervention
tighten
weaken
widen
worsen
lengthen