Twisted roots used for a perch (5)
I believe the answer is:
roost
'for a perch' is the definition.
(roost is a kind of perch)
'twisted roots' is the wordplay.
'twisted' indicates an anagram.
'roots' anagrammed gives 'ROOST'.
'used' is the link.
(Other definitions for roost that I've seen before include "where fliers land" , "Perch where bird sleeps" , "suitable sleeping-place" , "Colony of bats; perch" , "Glowing with joy" .)