GBS and RLS, for example (3,2,7)
I believe the answer is:
men of letters
'gbs' is the definition.
Although both the answer and definition are plural nouns, I can't understand how they can define each other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for men of letters that I've seen before include "scholars" , "Royal Mail employees" .)