Romeo in a church is most experienced (4)
I believe the answer is:
arch
'most experienced' is the definition.
The answer and definition are different parts of speech. However, adjectives and past participle verbs can occasionally mean the same thing.
'romeo in a church' is the wordplay.
'romeo' becomes 'R' (phonetic alphabet: alpha, bravo, charlie etc.).
'in' indicates putting letters inside.
'church' becomes 'ch' (common abbreviation).
'a'+'ch'='ach'
'r' put within 'ach' is 'ARCH'.
'is' acts as a link.
Can you help me to learn more?
(Other definitions for arch that I've seen before include "Chief: crafty" , "Curvature" , "Chief - supporter - cunning" , "Instep of foot" , "Curve of a bridge" .)