The Collaborative International Dictionary of English v.0.48:

Rite \Rite\, n. [L. ritus; cf. Skr. r[imac]ti a stream, a
   running, way, manner, ri to flow: cf. F. rit, rite. CF.
   Rivulet.]
   The act of performing divine or solemn service, as
   established by law, precept, or custom; a formal act of
   religion or other solemn duty; a solemn observance; a
   ceremony; as, the rites of freemasonry.
   [1913 Webster]

         He looked with indifference on rites, names, and forms
         of ecclesiastical polity.                --Macaulay.
   [1913 Webster]

   Syn: Form; ceremony; observance; ordinance.
        [1913 Webster]

WordNet (r) 3.0 (2006):

rite
    n 1: an established ceremony prescribed by a religion; "the rite
         of baptism" [syn: rite, religious rite]
    2: any customary observance or practice [syn: ritual, rite]

The Devil's Dictionary (1881-1906):

RITE, n.  A religious or semi-religious ceremony fixed by law, precept
or custom, with the essential oil of sincerity carefully squeezed out
of it.