Applauds power demands (8)
I believe the answer is:
acclaims
'applauds' is the definition.
(acclaiming is a kind of applauding)
'power demands' is the wordplay.
'power' becomes 'AC' (AC is an example).
'demands' becomes 'claims' (claim is a kind of demand).
'ac'+'claims'='ACCLAIMS'
(Other definitions for acclaims that I've seen before include "Hails, lauds" , "Praises loudly" , "Praises vociferously" , "Extols, lauds" , "Cheers" .)