co-ed I. \ˈkō|ed sometimes ̷ ̷ˈ ̷ ̷\noun (-s) Etymology: short for coeducational (student) : a female student in a coeducational institution II. adjective 1.: coeducational < co-ed schools > 2.: of, for, relating to, or being a co-ed < co-ed hairdos > 3.: for both men and women < a bill that would make the Army and Air National Guard co-ed — Springfield (Massachusetts) Union >