1protect (something) by interposing material that prevents the loss of heat or the intrusion of sound:insulate and draught-proof your home (as adjective insulated)an insulated loft
prevent the passage of electricity to or from (something) by covering it in non-conducting material:the case is carefully insulated to prevent short circuits
protect (someone or something) from unpleasant influences or experiences:the service is insulated from outside pressures
2 archaic make (land) into an island:the village was insulated by every flood of the river