do for
done for
To cause the death or ruin of; cause to fail. Used usually in the passive form done for.
The poor fellow is done for and will die before morning.
If Jim fails that test, he is done for.
do one a good turn
To perform an act of kindness, friendship, or help to another person, unselfishly, without expectation of reward.
"I'll be happy to help you any time you need it," John said. "After all you have done me so many good turns."
do one good
do one's heart good
To give satisfaction; please; gratify. To benefit.
It does my heart good to see those children play.
The fresh air will do you good after having been inside the house all day.
do one's best
To perform at one's optimum capacity; spare no effort in fulfilling one's duties.
"I've really done my best teaching you people," the tired professor said on the last day of classes. "I hope you got something out of this course."
do one's bit
do one's part
To shoulder one's share of responsibility in a communal undertaking; shirk one's obligation.
"Let me go home and rest, fellows, " John said. "I think I've done my bit for this project."
do one's thing
do one's own thing
To do what one does well and actually enjoys doing.
Two thousand fans paid $15 each to hear the rock group do their thing.
To follow one's bent; for example, to be engaged in left-wing politics, some sort of meditation, or use of drugs (particularly in the sixties).
The hippies were doing their own thing when the cops came and busted them.
To be engaged in an unusual activity that strikes others as odd.
Leave Jim alone, he's just doing his own thing when he's standing on his head.
do one's worst
To do one's utmost by resorting to every foul means possible.
Hitler did his worst to drive out the Allied invasion from Europe, but he failed.
do someone out of something
To cause to lose by trickery or cheating.
The clerk in the store did me out of $2.00 by overcharging me.