drop out is a verb meaning "give up in the face of defeat of lacking hope; admit defeat". It carries 3 recorded senses.
give up in the face of defeat of lacking hope; admit defeat
“In the second round, the challenger gave up”
withdraw from established society, especially because of disillusion with conventional values
“She hasn't heard from her brother in years--he dropped out after moving to California”
leave school or an educational program prematurely
“Many students drop out because they are not prepared for our challenging program”
Definitions, synonyms and semantic relations for drop out come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.