Noun has 2 senses

• school day(n = noun.time) - any day on which school is in session; "go to bed early because tomorrow is a school day"


• school day(n = noun.time) school, schooltime - the period of instruction in a school; the time period when school is in session; "he didn't miss a single day of school"; "stay after school"; "when the school day was done we would walk home together"