Some huff if typing Nina's number? (5)
I believe the answer is:
fifty
'number?' is the definition.
(fifty is a kind of number)
'some huff if typing nina's' is the wordplay.
'some' indicates a hidden word (some of the parts of the word are used).
'FIFTY' can be found hidden inside 'huff if typing nina'.
(Other definitions for fifty that I've seen before include "Half-century" , "A multiple of ten" , "L" .)