Leechlike (9)
I believe the answer is:
parasitic
'leechlike' is the definition.
(I know that leechlike can be written as parasitic)
This is all the clue.
(Other definitions for parasitic that I've seen before include "Sponging" , "Such threats" , "Living at another creature's expense" , "hanging on?" , "to be paid for by someone else" .)