1. One of four children born at the same time.

2. (Crystallog.)

Defn: A compound or twin crystal consisting of four individuals.

FOURNEAU
Four`neau", n. Etym: [F.] (Mil.)

Defn: The chamber of a mine in which the powder is placed.

FOUR-O'CLOCK
Four"-o'clock`, n.

1. (Bot.)

Defn: 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.)

Defn: The friar bird; — so called from its cry, which resembles these words.