bottle it
dishearten
nut up
gut up
throttle down
tamp down
lose one's nerve
puss out
fight down
reprove
choke back
disincentivize
box and lock
take the wind out of someone's sails
internalize
apostatise
tergiversate
apostatize
unmotivate
contradict
repulse
silence
wear
save one's breath to cool one's porridge
show the white feather
bottle
gag
spit it out
let someone down gently
throw something in someone's face
cut someone cold
scruple
chicken out
disbelieve
cramp someone's style
squash
mislike
borrow
cut
cede the field
dash
pall
frighten off
daunt
cold-shoulder
harumph
recant
demotivate
lose control
cut the ground from under someone's feet
put one's foot down on
scare
frighten away
scare away
bottle out
put the fear of God into
rain on someone's parade
piss on someone's bonfire
put one's foot down upon
scare off
take steps
wimp out
protest too much
redlight