Enormous hold close to foreshore (4)
I believe the answer is:
huge
'enormous' is the definition.
(synonyms)
'hold close to foreshore' is the wordplay.
'hold' becomes 'hug' (hug is a kind of hold).
'close to' says to take the final letters (the close of something is the end).
The final letter of 'foreshore' is 'e'.
'hug'+'e'='HUGE'
(Other definitions for huge that I've seen before include "giant" , "Extremely large" , "Massive" , "Great in size or amount" , "Unusually large" .)