In Noah’s day, part of the British Empire (4)
I believe the answer is:
shem
'in noah's day part' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'the british empire' is the wordplay.
'SHEM' is hidden within the letters.
However, I'm not sure how the hidden word is indicated.
'of' is the link.
Can you help me to learn more?
(Other definitions for shem that I've seen before include "One of Noah's sons" , "Eldest of Noah's three sons" , "Noah's eldest son" , "Biblical character" , "Third son of Noah" .)