adenosine(n = noun.substance) - (biochemistry) a nucleoside that is a structural component of nucleic acids; it is present in all living cells in a combined form as a constituent of DNA and RNA and ADP and ATP and AMP;
is a kind of nucleoside

adenosine, n. a nucleoside of adenine and ribose present in all living tissue in a combined form (see AMP, ADP, ATP).

Etymology:
ADENINE + RIBOSE

adenosine deaminase, adenosine diphosphate, adenosine monophosphate, adenosine triphosphate