'Excursus' definitions:

Definition of 'excursus'

(from WordNet)
noun
A message that departs from the main subject [syn: digression, aside, excursus, divagation, parenthesis]

Definition of 'Excursus'

From: GCIDE
  • Excursus \Ex*cur"sus\, n. [L., fr. excurrere, excursum. See Excurrent.] A dissertation or digression appended to a work, and containing a more extended exposition of some important point or topic. [1913 Webster]