Huge body of Dallas character holding up short item (7)
I believe the answer is:
jupiter
'huge body' is the definition.
'dallas character holding up short item' is the wordplay.
'dallas character' becomes 'jr'.
'holding' indicates putting letters inside.
'short' means to remove the last letter.
'item' with its final letter taken off is 'ite'.
'up'+'ite'='upite'
'jr' going around 'upite' is 'JUPITER'.
'of' is the link.
(Other definitions for jupiter that I've seen before include "Chief of the Gods, by Jove" , "celestial body" , "Planet - Roman equivalent of Zeus" , "Chief Roman god" , "Largest of the planets" .)