Lance with extremely sharp lug (5)
I believe the answer is:
spear
'lance' is the definition.
(I know this)
'with extremely sharp lug' is the wordplay.
'with' says to put letters next to each other.
'extremely' says to hollow out the word (remove centre letters) (only the extremes of the word are used).
'lug' becomes 'ear' (I've seen this before).
'sharp' with its centre taken out is 'sp'.
'sp' put next to 'ear' is 'SPEAR'.
(Other definitions for spear that I've seen before include "Weapon to throw" , "A bit of asparagus" , "Long pointed weapon" , "Shafted weapon for throwing or thrusting" , "Javelin or harpoon" .)