Four″–o'clock′ (?), n. 1. (Bot.) A plant of the genus Mirabilis. There are about half a dozen species, natives of the warmer parts of America. The common four-o'clock is M. Jalapa. Its flowers are white, yellow, and red, and open toward sunset, or earlier in cloudy weather; hence the name. It is also called marvel of Peru, and afternoon lady.
2. (Zoöl.) The friar bird; — so called from its cry, which resembles these words.