Young person seen regularly in brambles (4)
I believe the answer is:
babe
'young person' is the definition.
'regularly in brambles' is the wordplay.
'regularly in' means one should take alternating letters.
The alternate letters of 'brambles' are 'BABE'.
'seen' is the link.
(Other definitions for babe that I've seen before include "one up in arms" , "baby" , "Small child; -- Ruth, US?baseball player" , "Youngster" , "& 3 Down Famous baseball player" .)