Source : Webster's Revised Unabridged Dictionary (1913)

Disquisition \Dis`qui*si"tion\, n. [L. disquisitio, fr.
   disquirere to inquire diligently, investigate; dis- +
   quaerere to seek. See {Quest}.]
   A formal or systematic inquiry into, or discussion of, any
   subject; a full examination or investigation of a matter,
   with the arguments and facts bearing upon it; elaborate
   essay; dissertation.

         For accurate research or grave disquisition he was not
         well qualified.                          --Macaulay.

Source : WordNet®

disquisition
     n : an elaborate analytical or explanatory essay or discussion