B

Pronunciation (US):

(GB):

IPA (US):

 Dictionary entry overview: What does B mean? 

• B (noun)
  The noun B has 7 senses:

1. aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil

2. originally thought to be a single vitamin but now separated into several B vitamins

3. a trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder

4. a logarithmic unit of sound intensity equal to 10 decibels

5. (physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter

6. the 2nd letter of the Roman alphabet

7. the blood group whose red cells carry the B antigen

  Familiarity information: B used as a noun is common.

 Dictionary entry details 

• B (noun)

Sense 1

Meaning:

Aerobic rod-shaped spore-producing bacterium; often occurring in chainlike formations; found primarily in soil

Classified under:

Nouns denoting animals

Synonyms:

B; bacillus

Hypernyms ("B" is a kind of...):

eubacteria; eubacterium; true bacteria (a large group of bacteria having rigid cell walls; motile types have flagella)

Hyponyms (each of the following is a kind of "B"):

Bacillus globigii; Bacillus subtilis; grass bacillus; hay bacillus (a species of bacillus found in soil and decomposing organic matter; some strains produce antibiotics)

Yersinia pestis (a bacillus bacterium that causes the plague; aerosolized bacteria can be used as a bioweapon)

anthrax bacillus; Bacillus anthracis (a species of bacillus that causes anthrax in humans and in animals (cattle and swine and sheep and rabbits and mice and guinea pigs); can be used a bioweapon)

Holonyms ("B" is a member of...):

genus Bacillus (type genus of the Bacillaceae; includes many saprophytes important in decay of organic matter and a number of parasites)

Sense 2

Meaning:

Originally thought to be a single vitamin but now separated into several B vitamins

Classified under:

Nouns denoting substances

Synonyms:

B; B-complex vitamin; B complex; B vitamin; vitamin B; vitamin B complex

Hypernyms ("B" is a kind of...):

water-soluble vitamin (any vitamin that is soluble in water)

Hyponyms (each of the following is a kind of "B"):

biotin; vitamin H (a B vitamin that aids in body growth)

niacin; nicotinic acid (a B vitamin essential for the normal function of the nervous system and the gastrointestinal tract)

folacin; folate; folic acid; pteroylglutamic acid; pteroylmonoglutamic acid; vitamin Bc; vitamin M (a B vitamin that is essential for cell growth and reproduction)

adermin; pyridoxal; pyridoxamine; pyridoxine; vitamin B6 (a B vitamin that is essential for metabolism of amino acids and starch)

hepatoflavin; lactoflavin; ovoflavin; riboflavin; vitamin B2; vitamin G (a B vitamin that prevents skin lesions and weight loss)

antipernicious anemia factor; cobalamin; cyanocobalamin; vitamin B12 (a B vitamin that is used to treat pernicious anemia)

aneurin; antiberiberi factor; thiamin; thiamine; vitamin B1 (a B vitamin that prevents beriberi; maintains appetite and growth)

pantothen; pantothenic acid (a vitamin of the vitamin B complex that performs an important role in the oxidation of fats and carbohydrates and certain amino acids; occurs in many foods)

inositol (an optically inactive alcohol that is a component of the vitamin B complex)

choline (a B-complex vitamin that is a constituent of lecithin; essential in the metabolism of fat)

Sense 3

Meaning:

A trivalent metalloid element; occurs both in a hard black crystal and in the form of a yellow or brown powder

Classified under:

Nouns denoting substances

Synonyms:

atomic number 5; B; boron

Hypernyms ("B" is a kind of...):

chemical element; element (any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter)

Holonyms ("B" is a substance of...):

borax (an ore of boron consisting of hydrated sodium borate; used as a flux or cleansing agent)

kernite (a light soft mineral consisting of hydrated sodium borate in crystalline form; an important source of boron)

Sense 4

Meaning:

A logarithmic unit of sound intensity equal to 10 decibels

Classified under:

Nouns denoting quantities and units of measure

Synonyms:

B; Bel

Hypernyms ("B" is a kind of...):

sound unit (any acoustic unit of measurement)

Sense 5

Meaning:

(physics) a unit of nuclear cross section; the effective circular area that one particle presents to another as a target for an encounter

Classified under:

Nouns denoting quantities and units of measure

Synonyms:

b; barn

Hypernyms ("b" is a kind of...):

area unit; square measure (a system of units used to measure areas)

Domain category:

atomic physics; nuclear physics; nucleonics (the branch of physics that studies the internal structure of atomic nuclei)

Sense 6

Meaning:

The 2nd letter of the Roman alphabet

Classified under:

Nouns denoting communicative processes and contents

Hypernyms ("B" is a kind of...):

alphabetic character; letter; letter of the alphabet (the conventional characters of the alphabet used to represent speech)

Holonyms ("B" is a member of...):

Latin alphabet; Roman alphabet (the alphabet evolved by the ancient Romans which serves for writing most of the languages of western Europe)

Sense 7

Meaning:

The blood group whose red cells carry the B antigen

Classified under:

Nouns denoting body parts

Synonyms:

B; group B; type B

Hypernyms ("B" is a kind of...):

blood group; blood type (human blood cells (usually just the red blood cells) that have the same antigens)

 Context examples 

“A” and “B” refer to cancer that is confined to the prostate.

(ABCD rating, NCI Dictionary)

This allele, which encodes mitochondrial ATP-binding cassette sub-family B member 6 protein, may play a role in the modulation of both synthesis and hemostasis of heme and porphyrins in mitochondria.

(ABCB6 wt Allele, NCI Thesaurus)

This allele, which encodes ATP-binding cassette sub-family B member 5 protein, is involved in the mediation of the transport of small molecules across membranes.

(ABCB5 wt Allele, NCI Thesaurus)

The four main blood types are A, B, O, and AB.

(ABO Blood Group, NCI Dictionary)

Velutin is able to inhibit the degradation of the inhibitor of nuclear factor kappa-B (NF-kB), thereby blocking the activation of NF-kB, as well as inhibiting phosphorylation of mitogen-activated protein kinase p38 and JNK.

(Acai Berry Juice, NCI Thesaurus)

T cells are significantly less susceptible than B cells to acadesine-induced apoptosis.

(Acadesine, NCI Thesaurus)

Human ABCB1-T allele is a variant form of the human ATP-binding cassette, sub-family B (MDR/TAP), member 1 (ABCB1) gene, located at 7q21.1, which encodes multidrug resistance protein 1.

(ABCB1 2 Allele, NCI Thesaurus)

Human ABCB1-C allele is the wild-type form of the human ATP-binding cassette, sub-family B (MDR/TAP), member 1 (ABCB1) gene (ABC gene family), located at located at 7q21.1, which encodes multidrug resistance protein 1.

(ABCB1 1 Allele, NCI Thesaurus)

They also used rhodamine B as a model for volatile organic pollutants, as its molecular structure closely resembles those of pollutants emitted by vehicles, industry and agriculture.

(Smog-eating graphene composite reduces atmospheric pollution, University of Cambridge)

The specifics of Proxima B's orbit are not yet established.

(Simulations show planet orbiting Proxima Centauri could have liquid water, Wikinews)