Part with land required for port (6)
I believe the answer is:
sunder
'part' is the definition.
(I've seen this in another clue)
I can't explain the remainder of the clue.
Can you help me to learn more?
(Other definitions for sunder that I've seen before include "Nursed so as to tear apart" , "Cut" , "Tear apart, sever" , "Split apart" , "Separate the odd red sun" .)