n. [ Gr. bh^ta. ] The second letter of the Greek alphabet, B, β. See B, and cf. etymology of Alphabet. Beta (B, β) is used variously for classifying, as: (a) (Astron.) To designate some bright star, usually the second brightest, of a constellation, as, β Aurigæ. (b) (Chem.) To distinguish one of two or more isomers; also, to indicate the position of substituting atoms or groups in certain compounds; as, β-naphthol. With acids, it commonly indicates that the substituent is in union with the carbon atom next to that to which the carboxyl group is attached. [ Webster 1913 Suppl. ]

{ ‖, n. Excessive or extended use of the b sound in speech, due to conversion of other sounds into it, as through inability to distinguish them from b, or because of difficulty in pronouncing them. [ Webster 1913 Suppl. ]

n. [ From beta, generic name of the beet. ] (Chem.) A nitrogenous base, C5H11NO2, produced artificially, and also occurring naturally in beet-root molasses and its residues, from which it is extracted as a white crystalline substance; -- called also lycine and oxyneurine. It has a sweetish taste. [ 1913 Webster ]

v. t. [ imp. Betook p. p. Betaken p. pr. & vb. n. Betaking. ] [ Pref. be- + take. ] 1. To take or seize. [ Obs. ] Spenser. [ 1913 Webster ]

2. To have recourse to; to apply; to resort; to go; -- with a reflexive pronoun. [ 1913 Webster ]

They betook themselves to treaty and submission. Burke. [ 1913 Webster ]

The rest, in imitation, to like arms
Betook them. Milton. [ 1913 Webster ]

Whither shall I betake me, where subsist? Milton. [ 1913 Webster ]

3. To commend or intrust to; to commit to. [ Obs. ] [ 1913 Webster ]

(Physics) a form of ionizing radiation emitted by radioactive substances (such as radium), more penetrating than alpha rays, and consisting of negatively charged electrons. The electrons are the same kind of particle as those of cathode rays, but have much higher velocities (about 35, 000 to 180, 000 miles per second). They are readily deflected by a magnetic or electric field. [ Webster 1913 Suppl. ]

n. a type of particle accelerator which accelerates a continuous beam of electrons to high speeds by means of the electric field produced by changing magnetic flux.
Syn. -- induction accelerator. [ WordNet 1.5 ]

pos>a. [ p. p. of OE. bitechen, AS. bet&aemacr_;can, to assign, deliver. See Teach. ] Delivered; committed in trust. [ Obs. ] [ 1913 Webster ]