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

facultative \fac"ultative\, a. l. facultas, -atis, faculty:
   cf. f. facultatif, g. fakultativ.
   1. having relation to the grant or exercise faculty, or
      authority, privilege, license, or the like hence,
      optional; as, facultative enactments, or those which
      convey a faculty, or permission; the facultative
      referendum of switzerland is one that is optional with the
      people and is necessary only when demanded by petition;
      facultative studies; -- opposed to obligatory and
      compulsory, and sometimes used with to.
      webster 1913 suppl.

   2. of such a character as to admit of existing under various
      forms or conditions, or of happening or not happening, or
      the like; specif.: biol. having the power to live under
      different conditions; as, a facultative parasite, a plant
      which is normally saprophytic, but which may exist wholly
      or in part as a parasite; -- opposed to obligate.
      webster 1913 suppl.

   3. physiol. pertaining to a faculty or faculties.

            in short, there is no facultative plurality in the
            mind; it is a single organ of true judgment for all
            purposes, cognitive or practical.     --j.
                                                  martineau.
      webster 1913 suppl.
see also:
obligatory compulsory obligate 

[2] : WordNet (r) 2.0

facultative
     adj 1: of or relating to the mental faculties
     2: able to exist under more than one set of conditions; "a
        facultative parasite can exist as a parasite or a
        saprophyte" ant: obligate
     3: granting a privilege or permission or power to do or not do
        something; "a facultative enactment"
     4: not compulsory; "facultative courses in the sciences"
see also:
obligate 

Facultative >> F Words
Facultative, definition of term: Facultative
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