Fancy boat docks by popular area east of ruin (6)
I believe the answer is:
marina
'fancy boat docks' is the definition.
Although both the answer and definition are singular nouns, I don't see how they can define each other.
'popular area east of ruin' is the wordplay.
'popular' becomes 'in' (something that's 'in' is fashionable).
'area' becomes 'a' (maths abbreviation).
'east of' means one lot of letters go next to another (some letters go to the right of others).
'ruin' becomes 'mar' (I've seen this before).
'in'+'a'='ina'
'ina' after 'mar' is 'MARINA'.
'by' acts as a link.
Can you help me to learn more?
(Other definitions for marina that I've seen before include "Yacht harbour" , "place to moor up?" , "Docking place for pleasure craft" , "boating facility" , "Base for pleasure boats" .)