One damsel, largely enthralled by peg gives number (7)
I believe the answer is:
itemise
'number' is the definition.
('number'->'itemize' is in my internal thesaurus and 'ize'->'ise')
'one damsel largely enthralled by peg' is the wordplay.
'one' becomes 'i' (roman numeral).
'damsel' becomes 'miss' (I've seen this before).
'largely' means to remove the last letter.
'enthralled by' means one lot of letters goes inside another ('enthral' can mean 'capture').
'peg' becomes 'tee' (tee is a kind of peg).
'miss' with its final letter taken away is 'mis'.
'mis' put into 'tee' is 'temise'.
'i'+'temise'='ITEMISE'
'gives' is the link.
(Other definitions for itemise that I've seen before include "Enumerate" , "List, state each object" , "break down" , "Set down separately" , "Using spell out" .)