Swingers, but there’s something square about them (5)
I believe the answer is:
doors
'swingers' is the definition.
Although both the answer and definition are plural nouns, I can't understand how one could define the other.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for doors that I've seen before include "Ways in and out" , "Swinging or sliding barriers" , "Barriers to entrances" , "Openings" , "Portals" .)