Applauds a demand in case of cabbies (8)
I believe the answer is:
acclaims
'applauds' is the definition.
(acclaiming is a kind of applauding)
'a demand in case of cabbies' is the wordplay.
'demand' becomes 'claim' (claiming is a kind of demanding**).
'in' indicates putting letters inside.
'case of' says to hollow out the word (remove centre letters) (outsides of).
'cabbies' with its centre taken out is 'cs'.
'claim' put within 'cs' is 'cclaims'.
'a'+'cclaims'='ACCLAIMS'
(Other definitions for acclaims that I've seen before include "Praises vociferously" , "Praises loudly" , "Hails, lauds" , "Extols, lauds" , "Cheers" .)