back up
To move backwards.
The train was backing up.
I couldn’t back my car up because there was a bicycle in the driveway behind me.
To help or be ready to help; stay behind to help; agree with and speak in support of.
Jim has joined the Boy Scouts and his father is backing him up.
The principal backs up the faculty.
Jim told us what had happened and Bob backed him up.
Ursula asked her friends to back her up when she went to court to fight a ticket for an illegal lane change on the highway.
To return to a previous thought.
Wait a minute. Could you back up and say that again?
To move behind (another fielder) in order to catch the ball if he misses it.
The shortstop backed up the second baseman on the throw.
fall back on
fall back upon
To retreat to.
The enemy made a strong attack, and the soldiers fell back on the fort.
To go for help to; turn to in time of need.
When the big bills for Mother's hospital care came, Joe was glad he had money in the bank to fall back on.
If Mr. Jones can't find a job as a teacher, he can fall back on his skill as a printer.
get one's dander up
get one's Irish up
get one's back up
To become or make angry or stubborn.
The boy got his dander up because he couldn't go to the store.
The children get the teacher's dander up when they make a lot of noise.
Fred got his back up when I said he was wrong.
Our criticisms of his actions just got his back up.