tautomer
Concise Oxford English Dictionary © 2008 Oxford University Press:
tautomer /ˈtɔːtəmə/
▶noun Chemistry each of two or more readily interconvertible isomers of a compound which exist together in equilibrium.
– derivatives
tautomeric /-ˈmɛrɪk/ adjective,
tautomerism /-ˈtɒmərɪz(ə)m/ noun.
tautomeric /-ˈmɛrɪk/ adjective,
tautomerism /-ˈtɒmərɪz(ə)m/ noun.
'tautomer' also found in these Oxford entries:

