A
carbocation the
ground state of which has delocalized (bridged) bonding
π- or
σ-electrons. (N.B. Allylic and benzylic carbocations are not considered nonclassical.)
Source:
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1145