Boy was clad, but deliberately not in the beginning (3)
I believe the answer is:
lad
'boy' is the definition.
(informal term for boy)
'clad but deliberately not in the beginning' is the wordplay.
'LAD' is hidden within the letters.
However, I'm unsure how the hidden word is indicated.
'was' is the link.
Can you help me to learn more?
(Other definitions for lad that I've seen before include "Son" , "Stable worker" , "Stable employee" , "Scottish lover" , "Shaver" .)