Dock ends of crude lance (6)
I believe the answer is:
pierce
'lance' is the definition.
(I know this)
'dock ends of crude' is the wordplay.
'dock' becomes 'pier' (I've seen this in another clue).
'ends of' means to remove the middle letters.
'crude' with its middle removed is 'ce'.
'pier'+'ce'='PIERCE'
(Other definitions for pierce that I've seen before include "Skewer; run through" , "Impale" , "Stick a pin in" , "Penetrate as with sharp object" , "Make hole in using pointed instrument" .)