turning point is a noun meaning "an event marking a unique or important historical change of course or one on which important developments depend". It carries 2 recorded senses.
an event marking a unique or important historical change of course or one on which important developments depend
“the agreement was a watershed in the history of both nations”
the intersection of two streets
“standing on the corner watching all the girls go by”
Definitions, synonyms and semantic relations for turning point come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.