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  1. Having the power of acting; exerting force, physical or moral; having or exerting agency; active in the production of effects. In actions of religion we should be zealous, active and operative, so far as prudence will permit. Taylor. It holds in all operative principles, especially in morality. South.
  2. Efficacious; producing the effect.


A laboring man, a laborer, artisan, or workman in manufactories.


  1. He or that which operates; he or that which produces an effect.
  2. In surgery, the person who performs some act upon the human body by means of the hand, or with instruments; as, a skillful operator.


or O-PER'CU-LA-TED a. [L. operculatus, from operio, to cover.] In botany, having a lid or cover, as a capsule. Martyn.

O-PER'CU-LI-FORM, a. [L. operculum, a lid, and form.]

Having the form of a lid or cover. Say.


  1. In botany, the lid of a pitcher-form leaf.
  2. The cover of the seed vessel of certain moss-like plants.
  3. In conchology, the plate which closes the orifice of a shell.

OP-ER-OSE, a. [L. operosus, from opera, operor.]

Laborious; attended with labor; tedious. Burnet.


The state of being laborious. More.


Laboriousness. [Not used.]

OPE-TIDE, n. [ope and tide.]

The ancient time of marriage from Epiphany to Ash-Wednesday. Bp. Hall.

O-PHI-CLEIDE, n. [Gr. οφις and κλεις.]

The largest brass wind instrument of the trumpet kind, used in the orchestra. It has a compass of three octaves.

O-PHID'I-AN, a. [Gr. οφις, a serpent.]

Pertaining to serpents; designating an order of vertebral animals destitute of feet or fins.

O-PHID'I-AN, n. [Gr. οφις, a serpent.]

An animal of the serpent kind, as the Boa, rattlesnake, adder and viper. The order is called Ophidia.

O-PHID'I-ON, n. [Gr. from οφις, a serpent.]

A fish of the anguilliform kind, resembling the common eel, but shorter, more depressed and of a paler color; found in the Mediterranean. Dict. Nat. Hist.


Pertaining to ophiology.


One versed in the natural history of serpents.

O-PHI-OL'O-GY, n. [Gr. οφις, serpent, and λογος, discourse.]

That part of natural history which treats of serpents, or which arranges and describes the several kinds. Ed. Encyc.

O-PHI-OM'AN-CY, a. [Gr. οφις, a serpent, and μαντεια, divination.]

In antiquity, the art of divining or predicting events by serpents, as by their manner of eating or by their coils. Encyc.

O-PHI-O-MORPH'OUS, a. [Gr. οφις, and μορφη, form.]

Having the form of a serpent. Ray.

O-PHI-OPH'A-GOUS, a. [Gr. οφις, a serpent, and φαγω, to eat.]

Eating or feeding on serpents. Brown.

O'PHITE, a. [Gr. οφις, a serpent.]

Pertaining to a serpent. Holwell.

O'PHITE, n. [Gr. οφις, a serpent, whence οφιτης, a stone spotted like a serpent.]

Green porphyry, or serpentine; a variety of greenstone of a dusky green color of different shades, sprinkled with spots of a lighter green; in other words, containing greenish white crystals of feldspar. Cleaveland.

OPH-I-U'CHUS, n. [Gr. οφιουχος; οφις, a serpent, and εχω, to have.]

A constellation in the northern hemisphere. Milton.

OPH-THAL'MIC, a. [See ophthalmy.]

Pertaining to the eye.

OPH-THAL-MOS'CO-PY, n. [Gr. οφθαλμος, the eye, and σκοπεω, to view.]

A branch of physiognomy which deduces the knowledge of a man's temper and manner from the appearance of the eyes. Encyc.