Along with Russian agreed to tour capital — it's a heavenly sight (9)
I believe the answer is:
andromeda
'a heavenly sight' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'along with russian agreed to tour capital' is the wordplay.
'along with' becomes 'and' (I've seen this in another clue).
'russian agreed' becomes 'da' ('yes' or 'agreed' in Russian).
'to tour' is an insertion indicator (to tour can mean to go around).
'capital' becomes 'Rome' (capital of Italy).
'and'+'da'='andda'
'andda' placed around 'rome' is 'ANDROMEDA'.
'it's' is the link.
Can you help me to learn more?
(Other definitions for andromeda that I've seen before include "Cassiopeia's daughter" , "Strangely, man adored the constellation" , "star group" , "plant" , "Greek maid seen in Milan" .)