Aback, a-bak′, adv. (naut.) said of sails pressed backward against the mast by the wind—hence (fig.) Taken aback, taken by surprise, [A.S. on bæc. See On and Back.]

Abacot. See Bycocket.

Abactinal, ab-ak′ti-nal, adj. (zool.) remote from the actinal area, without rays.—adv. Abac′tinally.

Abaction, ab-ak′shun, n. (law) the stealing of a number of cattle at once.—n. Abac′tor, one who does this. [L. abigĕre, abactum, to drive off.]

Abacus, ab′a-kus, n. a counting-frame or table: (archit.) a level tablet on the capital of a column, supporting the entablature:—pl. Ab′acī.—ns. Abacis′cus, Abac′ulus, dims. of Abacus; Ab′acist, one who counts with the abacus. [L.—Gr. abax, abakos, a board for reckoning on.]

Abaddon, a-bad′don, n. the destroyer, or angel of the bottomless pit: (Milton) the bottomless pit, or abyss of hell itself. [Heb., from ābad, to be lost.]

Abaft, a-baft′, adv. and prep. on the aft, hind, or stern part of a ship: behind. [Pfx. a-, for A.S. on, on, and bæftan, after, behind; itself made up of pfx. be-, and æftan. See Aft.]

Abalienate, ab-āl′yen-āt, v.t. Same as Alienate.

Abandon, a-ban′dun, v.t. to give up: to desert: to yield (one's self) without restraint (with to).—v.t. Aband′ (Spens.), to abandon.—n. Aban′don (n to be nasalised), freedom from conventional restraints: careless freedom of manners.—adj. Aban′doned, given up, as to a vice: profligate: completely deserted: very wicked.—adv. Aban′donedly.—n. Aban′donment, act of abandoning: state of being given up: enthusiastic surrender of self to a cause: (law) the renunciation of a claim. [O. Fr. bandon, from the Teut. root ban, proclamation, came to mean decree, authorisation, permission; hence à bandon—at will or discretion, abandonner, to give up to the will or disposal of some one. See Ban, Banns.]