in-service I. \(ˈ)in| ̷ ̷ ̷ ̷, ənˈ ̷ ̷ ̷ ̷\adjective : going on or continuing while in service < in-service training > < in-service care of delicate fabrics > II. adjective : of, relating to, or being one that is fully employed < in-service teachers > < in-service police officers >