Flower smaller than a cello (5)
I believe the answer is:
viola
'cello' is the definition.
(thesaurus)
'flower smaller than a' is the wordplay.
I cannot really understand how this works, but
'a' is present in the answer.
The remaining letters 'viol' is a valid word which might be clued in a way I don't understand.
This may be the basis of clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for viola that I've seen before include "Alto of the violin family" , "Pansy genus" , "Bowed instrument slightly larger than a violin" , "One played" , "String instrument of a range between the violin and cello" .)