- A bad break
- A bad hair day
- A bad workman always blames his tools
- A big ask
- A bigger bang for your buck
- A bird in the hand is worth two in the bush
- A bite to eat
- A blessing in disguise
- A bull and cow
- A bunch of fives
- A chip on your shoulder
- A diamond in the rough
- A dime a dozen
- A doubting thomas
- A drop in the bucket
- A fate worse than death
- A feather in ones cap
- A fish out of water
- A flash in the pan
- A fly in the ointment
- A fly on the wall
- A fool and his money are soon parted
- A fools paradise
- A foot in the door
- A golden key can open any door
- A hot potato
- A house divided against itself cannot stand
- A knight in shining armour
- A leopard cant change his spots
- A little bird told me
- A load of cobblers
- A load of codswallop
- A lot on your plate
- A man after my own heart
- A miss is as good as a mile
- A penny for your thoughts
- A penny saved is a penny earned
- A picture paints a thousand words
- A piece of cake
- A pig in a poke
- A place in the sun
- A red rag to a bull
- A safe pair of hands
- A sea change
- A shot in the arm
- A sight for sore eyes
- A skeleton in the closet
- A slap on the wrist
- A sledgehammer to crack a nut
- A sorry sight
- A stitch in time saves nine
- A stones throw
- A taste of your own medicine
- A thorn in my flesh
- A toss up
- A wolf in sheeps clothing
- About face
- About time
- Absence makes the heart grow fonder
- Abso bloody lutely
- Ace in the hole
- Achilles heel
- Across the board
- Act your age
- Actions speak louder than words
- Adage
- Adams ale
- Add fuel to the fire
- Add insult to injury
- Against the clock
- Agreement
- Aint my first rodeo
- Al desko
- Al fresco
- All at sea
- All bark and no bite
- All greek to me
- All in a days work
- All in all
- All kidding aside
- All set
- All the way
- All thumbs
- All to cock
- All together now
- Alley cat
- Alpha mom
- Alphabet soup
- Amber nectar
- America
- Amped up
- An act of god
- An arm and a leg
- An axe to grind
- An open and shut case
- Animals
- Ankle biter
- Aphorism
- Apples and pears
- As high as a kite
- At the drop of a hat
- Australian origin
- Away with the fairies