1.
to no longer take part in or be part of sth :
He has dropped out of active politics.
a word that has dropped out of the language
2.
to leave school, college, etc. without finishing your studies :
She started a degree but dropped out after only a year.
—related noun dropout (1)
3.
to reject the ideas and ways of behaving that are accepted by the rest of society
—related noun dropout (2)