The Collaborative International Dictionary of English v.0.48:

Administrative \Ad*min"is*tra`tive\
   ([a^]d*m[i^]n"[i^]s*tr[=a]`t[i^]v), a. [L. administrativus:
   cf. F. administratif.]
   Pertaining to administration; administering; executive; as,
   an administrative body, ability, or energy. --
   Ad*min"is*tra`tive*ly, adv.
   [1913 Webster]

WordNet (r) 3.0 (2006):

administrative
    adj 1: of or relating to or responsible for administration