put a damper on sth	ruin sth or make it less enjoyable
be in the dark about sth	be unaware of sth
don't give up your day job	continue to do·sth you know rather than trying sth new
in broad daylight	in full view of the public/easily seen
deal a blow to sb or sth	cause sb great difficulty or spoil their plans
be on the defensive	protect oneself because one feels insecure or threatened
by definition	having a quality simply because of what it is
(for) donkey's years	a very long time
on the dot	punctual, exactly on time
lend an ear	listen to sb in a careful and sympathetic way
play it by ear	act ina situation by responding to events rather than according to plan
ease off	reduce in degree, speed or intensity
at the cutting edge	at the forefront of (eg. technology
on edge	tense/nervous/ anxious
to no effect	unsuccessful; ineffective
(not) see eye to eye with sb	(dis)agree with sb
have an eye for	be good at judging, the worth/ quality of sth
more to sth/ sb than meets the eye	sth/ sb is more important/interesting than is first seen