It develops in the East and breaks round the West (4)
I believe the answer is:
dawn
'it develops in the east' is the definition.
The definition suggests a singular noun which matches the answer.
'and breaks round the west' is the wordplay.
'breaks' indicates anagramming the letters.
'round' means one lot of letters goes inside another.
'the west' becomes 'w' ('W' can be a synonym of 'west').
'and' is an anagram of 'dan'.
'dan' placed around 'w' is 'DAWN'.
Can you help me to learn more?
(Other definitions for dawn that I've seen before include "Light in East" , "Aurora was its goddess" , "Cockcrow" , "Aurora, poetically" , "Daybreak" .)