It identifies the persevering and industrious individual (7)
I believe the answer is:
sticker
'it identifies the persevering and industrious individual' is the definition.
The definition suggests a singular noun which matches the answer.
'it' is the wordplay.
I cannot quite understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
The remaining letters 'sicker' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sticker that I've seen before include "Determined person" , "Adhesive label" , "Person with staying power" , "he soldiers on!" , "Gummed label" .)