Heavily burdened (5)
I believe the answer is:
laden
'heavily burdened' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for laden that I've seen before include "'Burdened, oppressed (5)'" , "Encumbered" , "Eland (anag)" , "cargo aboard" , "Of ship, having taken on cargo" .)