Source : Webster's Revised Unabridged Dictionary (1913)

Descant \Des*cant"\ (d[e^]s*k[a^]nt"), v. i. [imp. & p. p.
   {Descanted}; p. pr. & vb. n. {Descanting}.] [From descant;
   n.; or directly fr. OF. descanter, deschanter; L. dis- +
   cantare to sing.]
   1. To sing a variation or accomplishment.

   2. To comment freely; to discourse with fullness and
      particularity; to discourse at large.

            A virtuous man should be pleased to find people
            descanting on his actions.            --Addison.