One’s lab insider spots town slamming physicist (5,6)
I believe the answer is:
isaac newton
'physicist' is the definition.
(Isaac Newton is an example)
'one's lab insider spots town slamming' is the wordplay.
'one's' becomes 'i's' (Roman numeral).
'lab insider' becomes 'a' (I can't explain this - if you can you should believe this answer much more).
'spots' becomes 'acne' (skin condition causing spots).
'slamming' indicates anagramming the letters (I've seen 'slammed' mean this).
'town' anagrammed gives 'wton'.
'is'+'a'+'acne'+'wton'='ISAAC NEWTON'
Can you help me to learn more?
(Other definitions for isaac newton that I've seen before include "he described it mathematically" , "Scientist who proposed the basic laws of motion" , "Lawmaker" , "English mathematician and physicist" , "Seventeenth to eighteenth century English physicist/mathematician" .)