a corps perdu
bang
bearishly
bluffly
bluntly
boorishly
brashly
brusquely
cavalierly
churlishly
crustily
curtly
dash
forthwith
gruffly
harshly
hastily
head over heels
headfirst
headforemost
headlong
heels over head
impetuously
impulsively
like a flash
like a thunderbolt
nastily
of a sudden
on short notice
plop
plump
plunk
pop
precipitantly
precipitately
precipitously
rashly
sharp
sharply
short
shortly
slap
slap-bang
smack
snippily
startlingly
sudden
suddenly
corruptly