One who examines worker eating crumbled Lays (7)
I believe the answer is:
analyst
'one who examines' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'worker eating crumbled lays' is the wordplay.
'worker' becomes 'ant' (worker is a type of ant).
'eating' means one lot of letters goes inside another.
'crumbled' indicates an anagram.
'lays' anagrammed gives 'alys'.
'ant' enclosing 'alys' is 'ANALYST'.
Can you help me to learn more?
(Other definitions for analyst that I've seen before include "one involved in breakdown" , "Student of eg systems or psyche" , "Expert who examines and dissects, say systems" , "Freud, perhaps" , "Dealer with systems - shrink!" .)