The Collaborative International Dictionary of English v.0.48:

Monitory \Mon"i*to*ry\, n.
   Admonition; warning; especially, a monition proceeding from
   an ecclesiastical court, but not addressed to any one person.
   [1913 Webster] Monitress

The Collaborative International Dictionary of English v.0.48:

Monitory \Mon"i*to*ry\, a. [L. monitorius.]
   Giving admonition; instructing by way of caution; warning.
   [1913 Webster]

         Losses, miscarriages, and disappointments, are monitory
         and instructive.                         --L'Estrange.
   [1913 Webster]

WordNet (r) 3.0 (2006):

monitory
    adj 1: serving to warn; "shook a monitory finger at him"; "an
           exemplary jail sentence" [syn: admonitory,
           cautionary, exemplary, monitory, warning(a)]