OROLOGY
O*rol"o*gy, n. Etym: [Gr. -logy: cf. F. orologie.]

Defn: The science or description of mountains.

OROMETER
O*rom"e*ter, n. [Gr. mountain + -meter.] (Meteor.)

Defn: An aneroid barometer having a second scale that gives the approximate elevation above sea level of the place where the observation is made.

OROTUND O"ro*tund`, a. Etym: [L. os, oris, the mouth + rotundus round, smooth.]

Defn: Characterized by fullness, clearness, strength, and smoothness; ringing and musical; — said of the voice or manner of utterance. — n.

Defn: The orotund voice or utterance Rush.

OROTUNDITY
O`ro*tun"di*ty, n.

Defn: The orotund mode of intonation.

ORPHALINE
Or"pha*line, n.