As worn by Bert out East? (5)
I believe the answer is:
beret
'as worn by' is the definition.
I can't judge whether this definition defines the answer.
'bert out east?' is the wordplay.
'out' means one lot of letters goes inside another.
'east?' becomes 'e' (synonyms).
'bert' enclosing 'e' is 'BERET'.
Can you help me to learn more?
(Other definitions for beret that I've seen before include "Flat French cap" , "Soft round cap without a peak" , "French-style hat" , "Soft peak-less kind of cap" , "cover for commandos" .)