The most common and most likely answer to this crossword clue is the 8 letter word PEDIMENT
P
E
D
I
M
E
N
T
More clues leading to the result PEDIMENT
- Architectural feature may be obstacle having ignored first two letters
- Grey borders in extension covered by dearest architectural feature
- Topping feature one metre from bar
- Triangular feature in gym — mend it when broken
- Bit of money put into top-floor flat’s architectural feature
- Architectural feature mapped — I’m enthralled somewhat
- Part of Temple Bar I’m missing
- US money in closed-up part of classical building
Buddy explains!

The straight part
We know that "part of classical building" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case part of classical building = pediment.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does PEDIMENT mean?
PEDIMENT noun- A classical architectural element consisting of a triangular section or gable found above the horizontal superstructure (entablature) which lies immediately upon the columns; fronton.