having a full plate

active unavailable working

buried employed engaged engrossed hustling occupied overloaded persevering slaving snowed swamped

already taken assiduous at it diligent having enough on one's plate having fish to fry having many irons in the fire in a meeting in conference in someone else's possession in the field in the laboratory industrious on assignment on duty on the go tied-up up to one's ears with a customer

idle

inactive unoccupied

lazy quiet unbusy unemployed unengaged