b

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The second letter of the modern English alphabet.
2. n. Any of the speech sounds represented by the letter b.
3. n. The second in a series.
4. n. Something shaped like the letter B.
5. n. The second best or second highest in quality or rank: a mark of B on an English theme.
6. n. Music The seventh tone in the scale of C major or the second tone in the relative minor scale.
7. n. Music A key or scale in which B is the tonic.
8. n. Music A written or printed note representing this tone.
9. n. Music A string, key, or pipe tuned to the pitch of this tone.
10. n. One of the four major blood groups in the ABO system. Individuals with this blood group have the B antigen on the surface of their red blood cells, and the anti-A antibody in their blood serum.
11. abbr. Physics barn
12. abbr. bel.
13. abbr. bottom quark
14. abbr. breadth.

Century Dictionary and Cyclopedia

1. The second letter in order in the English alphabet, as it was in the Phenician, and has been in most other alphabets derived from the Phenician. (See A.) The name of the Phenician character was beth, meaning house; from this comes the Greek name, beta. The Phenician beth, with some early Greek and Latin forms of b, and with the ancient Egyptian characters, hieratic and hieroglyphic, from which the others are by many authorities supposed to be ultimately derived, are given below: The value of the character is the same in all these alphabets. It is a labial sonant (or voiced) mute (or stop, or check); that is, it is made with the lips alone, by a complete closure cutting off all exit of breath from the mouth, but with accompanying sonant vibrations of the vocal chords, the current of air necessary to produce this being driven from the lungs into the closed cavity of the mouth. The corresponding surd (or voiceless) mute is p. (See P.) B has nothing of that variety of pronunciation shown by most English letters; but it is sometimes silent, as when final after m, in lamb, limb, tomb, thumb, and in a few other cases, as debt, doubt. In most of these cases b is a modern graphic insertion, and was never pronounced (in the English forms); e.g., limb, thumb, debt, doubt. In the fundamental or Germanic part of our language a b comes from a more original aspirate found in Sanskrit as bh, in Greek as φ (ph), in Latin usually as feminine Examples are: E. brother = Skt. bhrātar = Gr. φράτηρ = Latin frater; English bear (v.) = Skt. √ bhar = Gr. φέρειν = Latin ferre. With the English b corresponds that of most of the other Germanic dialects. In the original Indo-European or Aryan language b was nearly or altogether wanting.
2. As a numeral, B was used by the Hebrews and Greeks, as now by the Arabians, for 2.
3. As a symbol: In music, the seventh tone, or “leading tone,” of the model diatonic scale, or scale of C. B was the last tone to be adopted into the modern major scale. It was the first note to be modified by lowering its pitch a semitone; its two forms, the b rotundum or B flat (♭) and the b quadratum or B natural (♮) (see below), afterward became conventional signs which were applied as accidentals to all the notes of the scale. See accidental, n., 1. In Italian and French the same note is called si. In German use B denotes B flat, while B natural is represented by H, and is called ha.
4. In chem., the symbol of boron.
5. In ornithology, the accessory femorocaudal muscle, one of the chief classificatory muscles of the leg.
6. In mathematics, see A, 2 .
7. In abstract reasoning, suppositions, etc., the second or other person or thing mentioned: as, if A strike B.
8. In general, the second in any series: as, Company B (of a regiment), schedule B, etc.; in the form b, or b, the second column of a page, in a book printed in columns.
9. As an abbreviation, B. stands for— Bachelor (or Middle Latin Baccalaureus), in B. A. or A. B., B. C. E., B. D., B. L., B. M., etc. See these abbreviations. In dates, before, as in B. C. or B. C., and born, as in b. 1813. In a ship's log-book, in the form b., blue sky. In hydrometric measurements, Baumé: as, 8° B. See Baumé's hydrometer, under hydrometer. Also Bé.
10. or.

Wiktionary

1. n. The second letter of the basic modern Latin alphabet.
2. n. voiced bilabial plosive
3. n. The second letter of the English alphabet, called bee and written in the Latin script.
4. n. The ordinal number second, derived from this letter of the English alphabet, called bee and written in the Latin script.
5. abbr. Alternative form of b..
6. n. astronomy latitude in the galactic coordinate system
7. n. physics barn
8. n. computing bit
9. n. cricket bye

GNU Webster's 1913

1. is the second letter of the English alphabet. (See Guide to Pronunciation, §§ 196, 220.) It is etymologically related to p, v, f, w, and m, letters representing sounds having a close organic affinity to its own sound; as in Eng. bursar and purser; Eng. bear and Lat. ferre; Eng. silver and Ger. silber; Lat. cubitum and It. gomito; Eng. seven, Anglo-Saxon seofon, Ger. sieben, Lat. septem, Gr."epta`, Sanskrit saptan. The form of letter B is Roman, from the Greek B (Beta), of Semitic origin. The small b was formed by gradual change from the capital B.

WordNet 3.0

1. n. aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil
2. n. the blood group whose red cells carry the B antigen
3. n. originally thought to be a single vitamin but now separated into several B vitamins
4. n. the 2nd letter of the Roman alphabet
5. n. a logarithmic unit of sound intensity equal to 10 decibels
6. n. a trivalent metalloid element; occurs both in a hard black crystal and in the form of yellow or brown powder
7. n. (physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter