Dicky reveals unspecified number (7)
I believe the answer is:
several
'unspecified number' is the definition.
'several' can be an answer for 'number' (thesaurus). I'm unsure of the 'unspecified' bit.
'dicky reveals' is the wordplay.
'dicky' indicates anagramming the letters (dicky can mean ill or non-functioning).
'reveals' anagrammed gives 'SEVERAL'.
Can you help me to learn more?
(Other definitions for several that I've seen before include "A good few" , "Assorted" , "Indefinite number more than two or three, but not many" , "A few; separate" , "three or four" .)