Cobblers possibly tense standing up (8)
I believe the answer is:
desserts
'cobblers possibly' is the definition.
(cobbler is a type of dessert)
'tense standing up' is the wordplay.
'tense' becomes 'stressed' (I've seen this before).
'standing up' says the letters should be written in reverse (in a down clue up is reverse order).
'stressed' written backwards gives 'DESSERTS'.
(Other definitions for desserts that I've seen before include "Sweets" , "Final courses" , "Puddings" , "That may be cobblers" , "fools, perhaps?" .)