Idioms (starts with 'a'. part 1)

(feel) at home -to feel as if one belongs; to feel as if one were in one's home; to feel accepted.
I liked my dormitory room. I really felt at home there.
We will do whatever we can to make you feel at home.
Come on in. Sit down and feel at home.

abide by (something) — to follow the rules of something; to obey someone's orders.
John felt that he had to abide by his father's wishes.
If you want to be a member of this club, you are to abide by its rules.

able to breathe easily again —
1. Lit. able to breathe clean, fresh air with no restriction or obstruction.
After I got out of the dank basement, I was able to breathe easily again.
2. Fig. able to relax and recover from a busy or stressful time; able to catch one's breath. (Able to can be replaced with can.)
Final exams are over, so I can breathe easily again.

able to do (something) blindfolded -able to do something very easily, possibly without even looking. (Able to can be replaced with can.)
Bill boasted that he could pass his driver's test blindfolded.
Jim has always been a skilled worker; he does his job blindfolded.

able to take a joke — to be able to accept ridicule good-naturedly; to be able to be the object or butt of a joke willingly. (Able to can be replaced with can.)
Better not tease Ann. She can't take a joke.
Everybody is able to take a joke; I, for example, can’t stand when people make fun of me.

about time — this should have happened long ago It's about time that women's sports were treated the same as men's.
I think it's about time that our country invested in education.
I am very annoyed with you; it’s about time you minded your own business.

about to (do something) — to be on the point of doing something
We were about to leave the house when it started to rain.
She was about to leave when the phone rang.

above and beyond — (something) more than is required; greater than the required amount. (*Typically: be ~; go ~.)
The English teacher helped students after school every day, even though it was beyond the call of duty.
I appreciate your kindness; you did above and beyond to help me.

above reproach — not deserving of blame or criticism.
Some politicians behave as though they are above reproach.
Bill is a well-mannered young man; his behavior is above reproach.

above suspicion — [for one] to be honest enough that no one would suspect one; in a position where one could not be suspected. (This is a translation of words attributed to Julius Caesar, who divorced his wife, Pompeia, on the grounds of her possible involvement in a public scandal; Caesar stated, "Caesar's wife must be above suspicion.") (*Typically: be ~; keep oneself ~; remain ~.)
The general is a fine old man, completely above suspicion.
Henry acted as if he were above suspicion, but I am sure he is guilty.

absent-minded professor — a bumbling professor who overlooks everyday things.
Fred is such an absent-minded professor. He'd forget his head if it wasn't screwed on.
I don’t think much of Jack; he is so absent-minded.

according to Hoyle — according to the rules; in keeping with the way something is normally done. (Alludes to the rules for playing games. Edmond Hoyle wrote a widely used book with rules for card games. This expression is usually used for something other than games.)
That's wrong. According to Hoyle, this is the way to do it.
According to Hoyle, the in-patients are not allowed to leave the hospital grounds.

acid test — a test whose findings are beyond doubt or dispute.