The big top is the great tent a travelling show performs in. Under the big top.
It went up and came down in a day, which was the whole trick of a travelling circus. A big top could seat several thousand and was held up by masts called king poles.
1nounbig topThe great tent a travelling show performs in.
“The big top was up by noon and full by seven.”
big top is a tent.
Big plus top, from the American circus of the nineteenth century.
From big + top.
Etymology from Wiktionary, CC BY-SA
Practised in Circus & Fairground