This meaning describes education, housing, sports, or activities open to both male and female participants or to multiple genders.
The school became coed in the 1970s.
They joined a coed volleyball league.
This dated and potentially patronizing use refers specifically to a woman studying at a mixed-gender institution.
Old films often used coed to mean a female college student.
The magazine portrayed her as a typical young coed.
This less common informal noun refers to a mixed-gender school, group, team, residence, or event.
The academy changed from all-male to coed.
This tournament is a coed.