Tool to grip and lift weights, holding grams (5)
I believe the answer is:
tongs
'tool' is the definition.
(thesaurus)
'weights holding grams' is the wordplay.
'weights' becomes 'tons' (ton is a kind of weight).
'holding' is an insertion indicator.
'grams' becomes 'g' (abbreviation).
'tons' placed around 'g' is 'TONGS'.
'to grip and lift' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for tongs that I've seen before include "Grasping tool; Chinese secret societies" , "Item of tableware" , "Curling -, sugar -" , "Tool used for picking up things" , "Instrument for gripping and lifting" .)