Wordnet 3.0
NOUN (1)
1.
(rhetoric) the introductory section of an oration or discourse;
The Collaborative International Dictionary of English v.0.48:
Exordium \Ex*or"di*um\ (-[u^]m), n.; pl. E. Exordiums
(-[u^]mz), L. Exordia (-[.a]). [L. fr. exordiri to begin a
web, lay a warp, begin; ex out + ordiri to begin a web,
begin; akin to E. order. See Order.]
A beginning; an introduction; especially, the introductory
part of a discourse or written composition, which prepares
the audience for the main subject; the opening part of an
oration. "The exordium of repentance." --Jer. Taylor. "Long
prefaces and exordiums. " --Addison.
[1913 Webster]
WordNet (r) 3.0 (2006):
exordium
n 1: (rhetoric) the introductory section of an oration or
discourse