1. [obsolete] Association between a base and its conjugate acid through a hydrogen bond (B … HB+ or AH … A). Homoassociation is a more appropriate term for this phenomenon.
  2. The orbital overlap of two π-systems separated by a non-conjugating group, such as CH2.
    See also: conjugate acid–base pair, conjugated system, homoaromatic
PAC, 1994, 66, 1077. 'Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)' on page 1121 (https://doi.org/10.1351/pac199466051077)