boil
to go off the boil

cock
to go off at half cock

deep
to go off the deep end

faint
to go off in a faint

go off
to go off to sleep

go off with
fugir com

half-cock
to go off at half-cock

heavily
to go off heavily

off-line
to go off-line

rail
...to go off the rails / to run off the rails

scouting
to go off scouting

swoon
to go off in a swoon

tack
to go off on a new tack

tail
.../ to go off with one's tail between one's legs /... with one's tail between one's legs

tangent
to go off at a tangent

tear
to go off on a tear