Definition from Wiktionary, the free dictionary
vicinal (not comparable)
- Of or pertaining to a neighborhood; neighboring.
- (chemistry) Describing identical atoms or groups attached to nearby (especially adjacent) atoms in a molecule.
- (mineralogy) Describing subordinate planes on a crystal, which are very near to the fundamental planes in angles, and sometimes take their place.
of or pertaining to a neighborhood
chemistry: describing atoms attached to nearby atoms