Circus and Rings

Circus noun - A large usually roofless building for sporting events with tiers of seats for spectators.

Rings and circus are semantically related In some cases you can replace term "Rings" with "Circus", this nouns are similar.

Rings noun - Gymnastic apparatus consisting of a pair of heavy metal circles (usually covered with leather) suspended by ropes; used for gymnastic exercises.

Circus and rings are semantically related in circle topic. Sometimes you can use "Circus" instead a noun "Rings".