1. plural of rhea; large flightless birds native to South America, similar to ostriches but smaller

Examples

• Rheas are the largest birds in South America.
• The zoo’s new exhibit features two adult rheas.
• Unlike ostriches, rheas have three toes on each foot.
• Rheas can run up to 40 miles per hour when threatened.
• The male rheas are responsible for incubating the eggs.
• Rheas inhabit grasslands and open plains in Argentina and Brazil.