go into retreat—retire temporarily to a place of seclusion (to concentrate on a task, etc.):
- Narcissus goes into retreat to meditate, and Goldmund, not understanding Narcissus and his fear of loving, feels alone.
go on retreat—go to a specific place for the purpose of relaxation or recreation:
- She regains her sense of peace by going on a religious retreat with her church group.
Note: Neither expression correlates in meaning with the phrase beat the retreat—
1. give the signal to retreat:
- Even when Hitler was forced to beat a retreat on the Russian front … Spanish support did not waver.
2. withdraw from an undertaking, etc.:
- She beat the retreat when she realized that she was going to get nothing further out of him.
3. (U.S. Army) perform the routine consisting of marching and military music, usually at dusk:
- At 6 P.M. the Marines will beat the retreat with the town mayor taking the salute.