Hidden in underground cell, edges away from rodents (7)
I believe the answer is:
cryptic
'hidden' is the definition.
(I've seen this before)
'underground cell edges away from rodents' is the wordplay.
'underground cell' becomes 'crypt' (I've seen this before).
'edges away from' means to look at the middle letters.
'rodents' becomes 'mice' (mouse is a kind of rodent).
The middle letters of 'mice' are 'ic'.
'crypt'+'ic'='CRYPTIC'
'in' is the link.
(Other definitions for cryptic that I've seen before include "Mysteriously obscure" , "Esoteric" , "Like our other puzzle" , "Mysterious, obscure" , "(Of crossword) withindirect clues" .)