cold feet
• loss of nerve or confidence.
• "after arranging to meet I got cold feet and phoned her saying I was busy"
Similar:
hesitate,
falter,
delay,
drag one's feet,
stall,
think twice,
change one's mind,
waver,
oscillate,
fluctuate,
vacillate,
be undecided,
be indecisive,
be irresolute,
see-saw,
yo-yo,
haver,
hum and haw,
sit on the fence,
dilly-dally,
shilly-shally,
pussyfoot around,
blow hot and cold,