Definitions for guanineˈgwɑ nin
Random House Webster's College Dictionary
a purine base, C5H5N5O, that is a fundamental constituent of DNA and RNA, in which it forms base pairs with cytosine.
Ref: Symbol: G 4 6 2; Compare guanosine.
Origin of guanine:
1845–55; guan (o ) + -ine2
a purine base found in DNA and RNA; pairs with cytosine
A substance first obtained from guano; it is a nucleic base and pairs with cytosine in DNA and RNA.
Origin: From guano + -ine.