Body part seen in northern resort from time to time (3)
I believe the answer is:
toe
'body part' is the definition.
(toe is a kind of body part)
'northern resort from time to time' is the wordplay.
'northern' is a reversal indicator (in a down clue, letters go up or 'north').
'from time to time' indicates alternate letters (letters removed on a regular basis).
The alternating letters of 'resort' are 'eot'.
'eot' in reverse letter order is 'TOE'.
'seen in' is the link.
(Other definitions for toe that I've seen before include "A foot division" , "Extremity of the body" , "One with sock on" , "Lower digit" , "Lower end or tip" .)