Shoot liquid in a narrow jet (6)
I believe the answer is:
squirt
'shoot liquid in a narrow jet' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for squirt that I've seen before include "Jet - insignificant person" , "Send liquid out in jet as from syringe" , "Force liquid out in a jet" , "Force liquid out - short or contemptible person" , "Thin jet of liquid" .)