High part of building frequently involved in unskilled climbing (7)
I believe the answer is:
rooftop
'high part of' is the definition.
The definition suggests a singular noun which matches the answer.
'frequently involved in unskilled climbing' is the wordplay.
'frequently' becomes 'oft' (synonyms).
'involved in' means one lot of letters goes inside another.
'unskilled' becomes 'poor' (I've seen this in another clue).
'climbing' is a reversal indicator (in a down clue, letters climb up).
'poor' back-to-front is 'roop'.
'oft' placed within 'roop' is 'ROOFTOP'.
'building' is the link.
Can you help me to learn more?
(Other definitions for rooftop that I've seen before include "In place of protest" , "High point of building (from which to shout?)" , "Building's highest point" , "Building's upper surface" , "Highest point of dwelling" .)