Part 332

||Ap"sis (p"ss), n.; pl. Apsides (p"s*dz). See Apse. [L. apsis, absis, Gr. "apsi`s, "apsi^dos, a tying, fastening, the hoop of a wheel, the wheel, a bow, arch, vault, fr. "a`ptein to fasten.] 1. (Astron.) One of the two points of an orbit, as of a planet or satellite, which are at the greatest and least distance from the central body, corresponding to the aphelion and perihelion of a planet, or to the apogee and perigee of the moon. The more distant is called the higher apsis; the other, the lower apsis; and the line joining them, the line of apsides.

2. (Math.) In a curve referred to polar coördinates, any point for which the radius vector is a maximum or minimum.

3. (Arch.) Same as Apse.

Apt (&?;), a. [F. apte, L. aptus, fr. obsolete apere to fasten, to join, to fit, akin to apisci to reach, attain: cf. Gr. &?; to fasten, Skr. pta fit, fr. p to reach attain.] 1. Fit or fitted; suited; suitable; appropriate.

They have always apt instruments. Burke.

A river . . . apt to be forded by a lamb. Jer. Taylor.

2. Having an habitual tendency; habitually liable or likely; -- used of things.

My vines and peaches . . . were apt to have a soot or smuttiness upon their leaves and fruit. Temple.

This tree, if unprotected, is apt to be stripped of the leaves by a leaf-cutting ant. Lubbock.

3. Inclined; disposed customarily; given; ready; -- used of persons.

Apter to give than thou wit be to ask. Beau. & Fl.

That lofty pity with which prosperous folk are apt to remember their grandfathers. F. Harrison.

4. Ready; especially fitted or qualified (to do something); quick to learn; prompt; expert; as, a pupil apt to learn; an apt scholar. "An apt wit." Johnson.

Live a thousand years, I shall not find myself so apt to die. Shak.

I find thee apt . . . Now, Hamlet, hear. Shak.

Syn. -- Fit; meet; suitable; qualified; inclined; disposed; liable; ready; quick; prompt.

Apt, v. t. [L. aptare. See Aptate.] To fit; to suit; to adapt. [Obs.] " To apt their places." B. Jonson.

That our speech be apted to edification. Jer. Taylor.

Apt"a*ble (&?;), a. [LL. aptabilis, fr. L. aptare.] Capable of being adapted. [Obs.] Sherwood.

Ap"tate (&?;), v. t. [L. aptatus, p. p. of aptare. See Apt.] To make fit. [Obs.] Bailey

||Ap"te*ra (&?;), n. pl. [NL. aptera, fr. Gr. &?; without wings; 'a priv. + &?; wing, &?; to fly.] (Zoöl.) Insects without wings, constituting the seventh Linnæn order of insects, an artificial group, which included Crustacea, spiders, centipeds, and even worms. These animals are now placed in several distinct classes and orders.

Ap"ter*al (&?;), a. 1. (Zoöl.) Apterous.

2. (Arch.) Without lateral columns; -- applied to buildings which have no series of columns along their sides, but are either prostyle or amphiprostyle, and opposed to peripteral. R. Cyc.

Ap"ter*an (&?;), n. (Zoöl.) One of the Aptera.

||Ap*te"ri*a (&?;), n. pl. [NL. See Aptera.] (Zoöl.) Naked spaces between the feathered areas of birds. See Pteryliæ.

Ap"ter*ous (&?;), a. 1. (Zoöl.) Destitute of wings; apteral; as, apterous insects.

2. (Bot.) Destitute of winglike membranous expansions, as a stem or petiole; -- opposed to alate.

||Ap*ter"y*ges (&?;), n. pl. [NL. See Apteryx.] (Zoöl.) An order of birds, including the genus Apteryx.