Architect’s flyer (4)
I believe the answer is:
wren
This clue might be a double definition.
'architect's' is the first definition.
(Christopher Wren, 17th-century architect)
'flyer' is the second definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
Can you help me to learn more?
(Other definitions for wren that I've seen before include "Jenny?" , "Very small brown songbird (4)" , "A songster" , "A small garden bird" , "Tiny brown songbird with short erect tail" .)