Stand-up, say, having care of microphone (5)
I believe the answer is:
comic
'stand-up say' is the definition.
(I know that stand-up comedian is a type of comic)
'care of microphone' is the wordplay.
'care of' becomes 'co' (c/o can mean 'care of' when addressing mail).
'microphone' becomes 'mic'.
'co'+'mic'='COMIC'
'having' acts as a link.
(Other definitions for comic that I've seen before include "SECOND PART OF 16" , "Child's magazine" , "Children's periodical" , "Funny man, often stand-up" , "Funny; comedian" .)