Agreement is the preferred word. Agreeance is an obsolete word.
All in one piece vs All of a piece
All in one piece—(also: in one piece) without injury; relatively unharmed.
All in all vs In all
Note: The expression does not correlate in meaning with the phrase at all—under any circumstances.
Agree to vs Agree with
Agree to means to concede to something.
Anthropoid vs Anthropomorphic vs Anthropomorphous
Anthropoid, anthropomorphic and anthropomorphous all mean resembling man.
Answer vs Respond vs Reply vs Rejoin vs Retort
Answer, respond, reply, rejoin and retort (and their corresponding nouns answer, response, reply, rejoinder, retort) mean to say or write or sometimes to do something (or something that is said, written, or done) in return (as to a question, a call, a request, or a charge).
All in vs All out
Note: The expression does not correlate in meaning with the compound all-in—(attrib.) inclusive of everything:
Agnostic vs Atheist
An agnostic feels the existence of God cannot be proved or disproved.
Aggression vs Egression
Aggression refers to hostility.
Anodyne vs Opiate vs Narcotic vs Nepenthe
Anodyne, opiate, narcotic and nepenthe mean something used to dull or deaden one's senses or one's sensibility and are often used adjectivally.
All hands and the cook vs All the world and his wife
All the world and his wife—(also: every man and his dog ) lots of people; everyone of importance.
All fur coat and no knickers vs All hat and no cattle
All fur coat and no knickers—(UK derog.) said of a person or thing having an impressive appearance with no real substance beneath.