to cut short; cut off a part of; abridge; reduce; diminish.
Origin: 1425–75; late Middle English curtailen to restrict (said of royal succession or inheritance), probably a conflation of Middle French courtau(l)d (see curtal) and Middle English taillen to cut (see taille, tailor)
late 15c., from M.Fr. courtault "made short," from court "short," from L. curtus (see curt) + -ault pejorative suffix of Gmc. origin. Originally curtal; used of horses with docked tails, which probably influenced the spelling.