turn back is a verb meaning "retrace one's course". It carries 5 recorded senses.
force to go away; used both with concrete and metaphoric meanings
“Drive away potential burglars”
“drive away bad thoughts”
“dispel doubts”
“The supermarket had to turn back many disappointed customers”
Definitions, synonyms and semantic relations for turn back come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.