Send over some integral letters - this could be huge (5)
I believe the answer is:
large
'be huge' is the definition.
(similar in meaning)
'send over some integral letters' is the wordplay.
'send over' is a reversal indicator (I've seen 'sent over' mean this).
'some' indicates the answer is hidden within the clue (some parts of the word are used).
'egral' can be found hidden inside 'integral letters'.
'egral' backwards is 'LARGE'.
'this could' is the link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for large that I've seen before include "Big < burly" , "Stout" , "Extensive" , "Bumper" , "Lager (anag.)" .)