RNA

UK: /ˌɑːrɛnˈeɪ/

WordReference Random House Learner's Dictionary of American English © 2025

RNA, an abbreviation of:

1. Biochemistry, Genetics ribonucleic acid, any of a class of single-stranded nucleic molecules found chiefly in body cells and in certain viruses, important in making protein and in sending genetic material to new cells.

WordReference Random House Unabridged Dictionary of American English © 2025

RNA, [Genetics.]

1. Biochemistry, Genetics ribonucleic acid: any of a class of single-stranded molecules transcribed from DNA in the cell nucleus or in the mitochondrion or chloroplast, containing along the strand a linear sequence of nucleotide bases that is complementary to the DNA strand from which it is transcribed: the composition of the RNA molecule is identical with that of DNA except for the substitution of the sugar ribose for deoxyribose and the substitution of the nucleotide base uracil for thymine. Cf. messenger RNA, ribosomal RNA, transfer RNA. 

• 1945–50

Collins Concise English Dictionary © HarperCollins Publishers::

RNA noun

1. ribonucleic acid; any of a group of nucleic acids, present in all living cells, that play an essential role in the synthesis of proteins. On hydrolysis they yield the pentose sugar ribose, the purine bases adenine and guanine, the pyrimidine bases cytosine and uracil, and phosphoric acid
   See also messenger RNA, transfer RNA, ribosomal RNA, DNA1