Approximately under end of elephant's trunk (5)
I believe the answer is:
torso
'trunk' is the definition.
(both can mean a person's chest)
'approximately under end of elephant's' is the wordplay.
'approximately' becomes 'or so' (synonyms).
'under' is a charade indicator (letters next to each other) (in a down clue, some letters go below others).
'end of' suggests the final letters.
The last letter of 'elephant' is 't'.
'orso' put after 't' is 'TORSO'.
(Other definitions for torso that I've seen before include "Roots out in trunk of the body" , "Roost (anag)" , "part of body will be found" , "Piece of bronze" , "Body's trunk" .)