I have to support Aida, say -- tense worker (9)
I believe the answer is:
operative
'worker' is the definition.
(thesaurus)
'i have to support aida say tense' is the wordplay.
'i have' becomes 'ive'.
'to support' says to put letters next to each other (in a down clue, some letters hold others up).
'aida say' becomes 'opera' (Aida is an example).
'tense' becomes 't' (abbreviation used in many dictionaries).
'opera'+'t'='operat'
'ive' put after 'operat' is 'OPERATIVE'.
(Other definitions for operative that I've seen before include "Working (person)" , "Efficient" , "desired effect" , "secret agent" , "Machinist - working" .)