Why more said to be upset with large capacity? (5)
I believe the answer is:
roomy
'with large capacity?' is the definition.
'why more said to be upset' is the wordplay.
'why' becomes 'y'.
'said' shows a homophone (sound like).
'to be upset' says the letters should be written in reverse (I've seen 'being upset' mean this).
'more' sounds like 'moor'.
'y'+'moor'='ymoor'
'ymoor' back-to-front is 'ROOMY'.
(Other definitions for roomy that I've seen before include "Commodious" , "Broad" , "Without cramping" , "so wide" , "Having big space" .)