[1] : The Collaborative International Dictionary of English v.0.48

digression \digres"sion\, n. l. digressio: cf. f. digression.
   1. the act of digressing or deviating, esp. from the main
      subject of a discourse; hence, a part of a discourse
      deviating from its main design or subject.
      1913 webster

            the digressions i can not excuse otherwise, than by
            the confidence that no man will read them. --sir w.
                                                  temple.
      1913 webster

   2. a turning aside from the right path; transgression;
      offense. r.
      1913 webster

            then my digression is so vile, so base,
            that it will live engraven in my face. --shak.
      1913 webster

   3. anat. the elongation, or angular distance from the sun;
      -- said chiefly of the inferior planets. r.
      1913 webster

[2] : WordNet (r) 2.0

digression
     n 1: a message that departs from the main subject syn: aside,
          excursus, divagation, parenthesis
     2: a turning aside of your course or attention or concern; "a
        diversion from the main highway"; "a digression into
        irrelevant details"; "a deflection from his goal" syn: diversion,
         deviation, deflection, deflexion, divagation
     3: wandering from the main path of a journey syn: excursion
see also:
aside excursus divagation parenthesis diversion deviation 
deflection deflexion excursion 

[3] : Moby Thesaurus II by Grady Ward, 1.0

109 moby thesaurus words for "digression":
   aberrancy, aberration, ambages, apostrophe, aside, bend, bias,
   branching off, bypass, bypath, byway, circling, circuit,
   circuition, circuitousness, circuitry, circularity, circulation,
   circumambience, circumambiency, circumambulation, circumbendibus,
   circumflexion, circumlocution, circummigration, circumnavigation,
   corner, crook, crosswiseness, curve, declination, deflection,
   deflexure, departure, detour, deviance, deviancy, deviating,
   deviation, deviousness, diagonality, digressing, discursion,
   divagation, divarication, divergence, diversion, dogleg, double,
   drift, drifting, episode, errantry, excurse, excursion, excursus,
   exorbitation, gyre, gyring, hairpin, incident, indirection,
   indirectness, meandering, nonconformity, obiter dictum,
   obliqueness, obliquity, orbit, orbiting, parenthesis, pererration,
   rambling, roundabout, roundabout way, roundaboutness, rounding,
   sheer, shift, shifting, shifting course, shifting path, side path,
   side road, sidetrack, skew, skewness, slant, spiral, spiraling,
   squint, straying, sweep, swerve, swerving, swinging, tack,
   transverseness, turn, turning, twist, vagary, variation, veer,
   wandering, warp, wheeling, yaw, zigzag

Digression >> D Words
Digression, definition of term: Digression
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