[a. L. beta, Gr. βῆτα.]
1. The second letter of the Greek alphabet, Β, β.
a. 1300. Cursor M., 12425. Bot sai þou me first o betha, And siþen i sal þe sai alpha.
2. In various scientific uses; esp. a. Astron. Used to mark the second star in a constellation. b. Chem. The second of two or more isomerous modifications of the same organic compound. c. Nat. Hist. The second sub-species or permanent variety of a species. d. In various other classifications. Cf. ALPHA.
1867. Chambers, Astron., VI. ii. (1877), 492. Amongst the conspicuous stars β Libræ (green) appears to be the only instance.
1877. Watts, Fownes Chem., II. 497. Beta-orcin is obtained by dry distillation of usnic acid. Ibid. (1877), Dict. Chem., IV. 235. Stenhouse designated the acid obtained from South American Roccella as α-orsellic, and that prepared from South African Roccella as β-orsellic.