The Collaborative International Dictionary of English v.0.48:

Supervision \Su`per*vi"sion\, n.
   The act of overseeing; inspection; superintendence;
   oversight.
   [1913 Webster]

WordNet (r) 3.0 (2006):

supervision
    n 1: management by overseeing the performance or operation of a
         person or group [syn: supervision, supervising,
         superintendence, oversight]

Moby Thesaurus II by Grady Ward, 1.0:

39 Moby Thesaurus words for "supervision":
   accountability, administration, auspices, bossing, care, charge,
   civil government, conduct, direction, discipline, dispensation,
   disposition, empery, empire, eye, form of government, governance,
   government, handling, intendance, jurisdiction, management,
   oversight, political organization, polity, regime, regimen,
   regnancy, regulation, reign, responsibility, rule, running,
   sovereignty, superintendence, superintendency, surveillance, sway,
   system of government