A
A for effort
AA
Abide by (something)
Abide by a decision
Able to (do something) standing on one's head
Able to (do something) with one's eyes closed/shut
Able to breathe easily again
Able to breathe easily/freely again
Able to do (something) blindfolded
Able to take a joke
About time
About to (do something)
Above and beyond
Above average
Above board
Above par
Above reproach
Above suspicion
Absent-minded
According to Hoyle
Ace in the hole
Achilles' heel (of someone or something)
Aching heart
Acid test
Acquire a taste for (something)
Across the board
Act high and mighty
Act of God
Act one's age
Act up
AD
Add fuel to the fire
Add insult to injury
Add up
Add up (to something)
Adjourn a meeting
Advise against (something)
Afraid of one's own shadow
After a fashion
After all
After all is said and done
After hours
After one's own heart
After the fact
Against one's will
Against the clock
AGM
Ahead of one's time
Ahead of the game
Ahead of the pack
Ahead of time
AI
AIDS
Air (something) out
Air one's dirty laundry/linen in public
Air one's dirty linen in public
Air one's grievances
Albatross (around someone's neck)
Alive and well/kicking
All along
All at once
All day long
All ears
All eyes
All eyes are on (someone or something)
All for (someone or something)
All hands on deck
All in
All in (someone's) mind
All in a day's work
All in all
All in one breath
All in one piece
All manner of (someone or something)
All night long
All of a sudden
All over but the shouting
All over the place
All right
All rolled up in one
All set
All sweetness and light
All systems go
All talk (and no action)
All the rage
All the time
All thumbs
All to the good
All told
All-in-one
All-out-effort
Alley cat
Allow for (someone or something)
Almighty dollar
Along with (someone or something)
AM
Amount to (something)
Amount to the same thing
Answer to (someone)
Ante up
Any number of (someone or something)
AOB
AOK
APB
Appear out of nowhere
Apple of (one's) eye
Apple of (someone's) eye
Argue for the sake of arguing/argument
Arm and a leg
Arm in arm
Armed and dangerous
Armed to the teeth
Armpit of (somewhere)
Around the clock
Arrive on the scene
Arrow in one's quiver
As a duck takes to water
As a last resort
As a matter of fact
As a result of (something)
As a rule
As awkward as a cow on roller skates
As bald as a baby's backside
As bald as a coot
As black as a skillet
As black as a stack of black cats
As black as a sweep
As black as coal
As black as night
As black as pitch
As black as the ace of spades
As blind as a bat
As broad as a barn door
As busy as a beaver
As busy as a bee
As busy as a one-armed paperhanger
As busy as popcorn on a skillet
As calm as a toad in the sun
As clean as a hound's tooth
As conceited as a barber's cat
As cool as a cucumber
As crazy as a bedbug
As crazy as a loon
As crooked as a dog's hind leg
As dead as a dodo
As drunk as a skunk
As dry as a bone
As easy as ABC
As easy as apple pie
As easy as duck soup
As far as
As far as possible
As fat as a pig
As flat as a pancake
As free as a bird
As full/tight as a tick
As gaudy as a butterfly
As gentle as a lamb
As good as one's word
As graceful as a swan
As gruff as a bear
As happy as a clam
As happy as a lark
As hard as nails
As hoarse as a crow
As hungry as a bear
As innocent as a lamb
As long as
As luck would have it
As mad as a hornet