Met up in fall where there may be grounds (9)
I believe the answer is:
demitasse
'where there may be grounds' is the definition.
(tea set which may contain tea grounds)
'met up in fall' is the wordplay.
'met' becomes 'sat' (as in a parliament sitting or meeting).
'up' is a reversal indicator (in down clue: letters go upwards).
'in' indicates putting letters inside.
'fall' becomes 'demise'.
'sat' written backwards gives 'tas'.
'tas' going within 'demise' is 'DEMITASSE'.
(Other definitions for demitasse that I've seen before include "little cup" , "Coffee-cup" , "Small cup for black coffee" .)