IDIOMS N MEANS

A fool and his money are soon parted	This idiom means that people who aren't careful with their money spend it quickly. 'A fool and his money are easily parted' is an alternative form of the idiom.
A little bird told me	If someone doesn't want to say where they got some information from, they can say that a little bird told them.
A OK	If things are A OK, they are absolutely fine.
A poor man's something	Something or someone that can be compared to something or someone else, but is not as good is a poor man's version; a writer who uses lots of puns but isn't very funny would be a poor man's Oscar Wilde.
A snowball’s chance in hell	Something that has no likelihood of happening or succeeding: “Your proposal is too radical—it has a snowball’s chance in hell of being approved.”
A1	If something is A1, it is the very best or finest.
Abide by a decision	If you abide by a decision, you accept it and comply with it, even though you might disagree with it.
About face	If someone changes their mind completely, this is an about face. It can be used when companies, governments, etc, change their position on an issue.
Above board	If things are done above board, they are carried out in a legal and proper manner.
Absence makes the heart grow fonder	This idiom means that when people are apart, their love grows stronger.
Ace in the hole	A hidden advantage or resource kept in reserve until needed: “The coach was certain that his new trick play would turn out to be his ace in the hole.” This term comes from the game of stud poker, in which one or more cards are turned face down, or “in the hole,” as bets are placed. The ace is the card with the highest value.
Achilles’ heel	(uh-KIL-eez) A point of vulnerability.
Acid test	An acid test is something that proves whether something is good, effective, etc, or not.
Across the board	If something applies to everybody, it applies across the board.
Act of god	An event beyond human control—e.g., hurricane, earthquake, volcanic eruption (see volcano), etc.—for which there is no legal redress. The phrase is frequently used by insurance companies and lawyers.
Ad absurdum	(ad uhb-SUR-duhm) An argument whereby one seeks to prove one’s position by pointing out the absurdity or foolishness of an opponent’s position. Also, an argument carried to such lengths that it becomes silly or ridiculous. From Latin, meaning “to absurdity.”
Ad hoc	(ad HOK, ad HOHK) A phrase describing something created especially for a particular occasion: “We need an ad hoc committee to handle this new problem immediately.” From Latin, meaning “toward this (matter).”
Ad hominem	(ad HOM-uh-nem, ad HOM-uh-nuhm) A Latin expression meaning “to the man.” An ad hominem argument is one that relies on personal attacks rather than reason or substance.
Ad nauseam	(ad NAW-zee-uhm) To go on endlessly; literally, to continue “to seasickness”: “The candidate told us the details of how he overcame his childhood problems ad nauseam.”
Against the grain	If doing something goes against the grain, you're unwilling to do it because it contradicts what you believe in, but you have no real choice.
Agony aunt	An agony aunt is a newspaper columnist who gives advice to people having problems, especially personal ones.
Ahead of the pack	If you are ahead of the pack, you have made more progress than your rivals.
Albatross around one’s neck	An annoying burden: “That old car is an albatross around my neck.” Literally, an albatross is a large sea bird. The phrase alludes to Samuel Taylor Coleridge’s poem “The Rime of the Ancient Mariner,” in which a sailor who shoots a friendly albatross is forced to wear its carcass around his neck as punishment.
All and sundry	This idiom is a way of emphasising 'all', like saying 'each and every one'.