Definify.com
Webster 1913 Edition
Ethylidene
E-thyl′i-dene
.(Chem.)
An unsymmetrical, divalent, hydrocarbon radical,
C2H4
metameric with ethylene but written thus, CH3.CH=
to distinguish it from the symmetrical ethylene, CH2=CH2
. Its compounds are derived from aldehyde. Formerly called also ethidene
.