Demand rising, business gathering cheers (6)
I believe the answer is:
entail
'demand' is the definition.
(thesaurus)
'rising business gathering cheers' is the wordplay.
I cannot quite see how this works, but
'cheers' could be 'ta' (I've seen this in other clues) and 'ta' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for entail that I've seen before include "Call for" , "Need" , "Involve or require" , "Cut" , "Estate settled" .)