Government security agency almost charges Treasury scientist (7)
I believe the answer is:
chemist
'scientist' is the definition.
(I know that chemist is a type of scientist)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for chemist that I've seen before include "man of science" , "Pharmacist, say" , "He dispenses prescriptions" , "Pharmacist, professional who dispenses drugs etc" , "Nobel, say" .)