O.
Octavus, n. L. octavus, eighth; given in this book as a name to a suppositional plant.
Oil, n. From a Greek word meaning “olive oil.” An inflammable, greasy liquid extracted from certain vegetables, as olives, cotton seeds, nuts, etc.
Olive oil, n. The oil expressed from the fruit of the olive tree.
Orient, n. L. oriens, rising, as the sun; the East, the part of the horizon where the sun rises; Eastern countries, particularly Turkey, Persia, Egypt, India, China, etc.
Ovary cells, n. The cells which build up the ovary.
Ovule, n. L. ovum, an egg; a little egg. Applied to the rudimentary seeds of plants, which, upon fertilization and growth, become true seeds.
Ovule cells, n. The cells of which the ovule is formed.
Oxalis, n. From a Greek word meaning “acid”; a well-known plant, one form of which is called “wood sorrel.” It is called oxalis because of its acid juice.
Oxygen, n. One of the gases that compose the air and which is essential to life. It is also found in composition in the tissues of plants and animals.