to come or go into; to pass into the interior of; to pass within the outer cover or shell of; to penetrate; to pierce; as, to enter a house, a closet, a country, a door, etc.; the river enters the sea.-to unite in; to join; to be admitted to; to become a member of; as, to enter an association, a college, an army.-to engage in; to become occupied with; as, to enter the legal profession, the book trade, etc.-to pass within the limits of; to attain; to begin; to commence upon; as, to enter one's teens, a new era, a new dispensation.-to cause to go (into), or to be received (into); to put in; to insert; to cause to be admitted; as, to enter a knife into a piece of wood, a wedge into a log; to enter a boy at college, a horse for a race, etc.-to inscribe; to enroll; to record; as, to enter a name, or a date, in a book, or a book in a catalogue; to enter the particulars of a sale in an account, a manifest of a ship or of merchandise at the customhouse.-to go into or upon, as lands, and take actual possession of them.-to place in regular form before the court, usually in writing; to put upon record in proper from and order; as, to enter a writ, appearance, rule, or judgment.-to make report of (a vessel or her cargo) at the customhouse; to submit a statement of (imported goods), with the original invoices, to the proper officer of the customs for estimating the duties. see entry, 4.-to file or inscribe upon the records of the land office the required particulars concerning (a quantity of public land) in order to entitle a person to a right pf preemption.-to deposit for copyright the title or description of (a book, picture, map, etc.); as, "entered according to act of congress."-to initiate; to introduce favorably.-to go or come in; -- often with in used pleonastically; also, to begin; to take the first steps.-to get admission; to introduce one's self; to penetrate; to form or constitute a part; to become a partaker or participant; to share; to engage; -- usually with into; sometimes with on or upon; as, a ball enters into the body; water enters into a ship; he enters into the plan; to enter into a quarrel; a merchant enters into partnership with some one; to enter upon another's land; the boy enters on his tenth year; to enter upon a task; lead enters into the composition of pewter.-to penetrate mentally; to consider attentively; -- with into.