/ad"n in, -een', -uyn'/ , n.
Biochem. a purine base, C 5 H 5 N 5 , one of the fundamental components of nucleic acids, as DNA, in which it forms a base pair with thymine, and RNA, in which it pairs with uracil. Symbol: A
[ 1880-85; Adenin; see ADEN-, -INE 2 ]