1991 - Independent - These days Soviet visas are issued at the drop of a hat.
drop your aitches
fail to pronounce the h sound, especially at the beginning of words.
IN Britain, dropping your aitches is considered by some to be a sign of a lack of education or of inferior social class.
1903 - George Bernard Shaw - Man & Superman - This man takes more trouble to drop his aitches than ever his father did to pick them up.
drop the ball
make a mistake
mishandle things - North American informal
drop a brick
make an indiscreet or embarrassing remark - British informal
drop your bundle
become very nervous or upset
go to pieces – Australian
drop a clanger
make an embarrassing or foolish mistake - British informal
Dropping something that makes a loud clang attracts attention. This mid 20th-century expression is used especially in the context of a very embarrrassing or tactless act or remark made in a social situation.
1998 - Spectator - Yet he never escaped from his own nagging suspicion that he had somehow overachieved and that he was likely to drop a huge clanger at any moment.
die suddenly and unexpectedly
used as an expression of intense scorn or dislike - informal
This idiom is the source of the adjective drop-dead, which is used to emphasize how attractive someone or something is, as in drop-dead gorgeous.
drop the dime on = drop a dime on
inform on someone to the police - US informal
1990 - Scott Turow - The Burden of Proof - Dixon says he's thought it over, the best course for him is just to drop the dime on John.
drop your guard
relax your defensive posture, leaving yourself vulnerable to attack
reduce your level of vigilance or caution
This is an expression connected in its literal sense with boxing, as is its opposite of raise your guard meaning adopt a defensive posture.
drop a hint = drop hints
let fall a hint or hints, as if casually or unconsciously
drop someone like a hot potato = drop something like a hot potato
quickly abandon someone or something – informal
Drop here is used literally, but also in the figurative sense of end a social acquaintance with someone. A hot potato can be used independently as a metaphor for a controversial or awkward issue or problem that no one wants to deal with.
drop someone a line
send someone a note or letter in a casual manner
a drop in the ocean = a drop in a bucket
a very small amount compared with what is needed or expected
1995 - Ian Rankin - Let It Bleed - A few million was a drop in the ocean, hardly a ripple.
refer frequently to well-known people in such a way as to imply that they are close acquaintances
drop the pilot
abandon a trustworthy adviser
Dropping the Pilot was the caption of a famous cartoon by John Tenniel, published in Punch in 1890. It depicted Bismarck's dismissal as German Chancellor by the young Kaiser Wilhelm II.
drop your trousers
deliberately let your trousers fall down, especially in a public place
have the drop
on have the advantage over – informal
Have the drop on was originally a mid 19th-century US expression used literally to mean that you have the opportunity to shoot before your opponent can use their weapon.
2000 - Clay Shooting - He always seems to have the drop on me by one bird no matter how hard I try.