管用

efficacious / useful

variant of 管[guan3]

surname Guan

to take care (of) / to control / to manage / to be in charge of / to look after / to run / to care about / tube / pipe / woodwind / classifier for tube-shaped objects / particle similar to 把[ba3] in 管...叫 constructions / writing brush / (coll.) to / towards

to use / to employ / to have to / to eat or drink / expense or outlay / usefulness / hence / therefore