RA

Pronunciation (US):

(GB):

IPA (US):

 Dictionary entry overview: What does RA mean? 

• RA (noun)
  The noun RA has 3 senses:

1. an intensely radioactive metallic element that occurs in minute amounts in uranium ores

2. ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods

3. (astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours and minutes and seconds; used with declination to specify positions on the celestial sphere

  Familiarity information: RA used as a noun is uncommon.

 Dictionary entry details 

• RA (noun)

Sense 1

Meaning:

An intensely radioactive metallic element that occurs in minute amounts in uranium ores

Classified under:

Nouns denoting substances

Synonyms:

atomic number 88; Ra; radium

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

metal; metallic element (any of several chemical elements that are usually shiny solids that conduct heat or electricity and can be formed into sheets etc.)

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

uranium ore (any ore from which uranium can be extracted)

Sense 2

Meaning:

Ancient Egyptian sun god with the head of a hawk; a universal creator; he merged with the god Amen as Amen-Ra to become the king of the gods

Classified under:

Nouns denoting people

Synonyms:

Ra; Re

Instance hypernyms:

Egyptian deity (a deity worshipped by the ancient Egyptians)

Domain category:

antiquity (the historic period preceding the Middle Ages in Europe)

Sense 3

Meaning:

(astronomy) the equatorial coordinate specifying the angle, measured eastward along the celestial equator, from the vernal equinox to the intersection of the hour circle that passes through an object in the sky; usually expressed in hours and minutes and seconds; used with declination to specify positions on the celestial sphere

Classified under:

Nouns denoting spatial position

Synonyms:

celestial longitude; RA; right ascension

Context example:

one hour of right ascension equals fifteen degrees

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

angular distance (the angular separation between two objects as perceived by an observer)

Domain category:

astronomy; uranology (the branch of physics that studies celestial bodies and the universe as a whole)

 Context examples 

Isoform 2 is an autoantigen in rheumatoid arthritis but it is not specific to RA.

(Interleukin 6 Signal Transducer, NCI Thesaurus)

Multiple Sclerosis 1999; 5: 349-54). (Marrie RA and Goldman M. Validity of performance scales for disability assessment in multiple sclerosis.

(Patient Determined Disease Steps Questionnaire, NCI Thesaurus/CDISC)

And we fell back on the guitar-case, and the flower-painting, and the songs about never leaving off dancing, Ta ra la! and were as happy as the week was long.

(David Copperfield, by Charles Dickens)

ASAP-related proteins, ARAP1, 2 and 3 have Arf GAP, Rho GAP, Ankyrin repeat, Ras-associating (RA), and five PH domains, and therefore have the potential of integrating four signaling pathways.

(ADP-Ribosylation Pathway, NCI Thesaurus/BIOCARTA)

Threatened social interest species include a number of stingless bees (known locally as uruçu, mandaçaia, and jandaíra), swamp ghost crabs, blue land crabs, a freshwater shrimp locally known as pitu, mangrove root crabs, catfish, yellowmouth groupers, jewfish, hammerhead sharks, among others.

(Over 300 animal species threatened in Bahia, Agência Brasil)

After tea we had the guitar; and Dora sang those same dear old French songs about the impossibility of ever on any account leaving off dancing, La ra la, La ra la, until I felt a much greater Monster than before.

(David Copperfield, by Charles Dickens)

All I know of the rest of the evening is, that I heard the empress of my heart sing enchanted ballads in the French language, generally to the effect that, whatever was the matter, we ought always to dance, Ta ra la, Ta ra la! accompanying herself on a glorified instrument, resembling a guitar.

(David Copperfield, by Charles Dickens)