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

wednesday \wednes"day\ ?; 48, n. oe. wednesdai, wodnesdei,
   as. w=odnes daeg, i. e., woden's day a translation of l.
   dies mercurii; fr. w=oden the highest god of the teutonic
   peoples, but identified with the roman god mercury; akin to
   os. w=odan, ohg. wuotan, icel. oethinn, d. woensdag
   wednesday, icel. =oethinsdagr, dan.  sw. onsdag. see
   day, and cf. woden, wood, a.
   the fourth day of the week; the next day after tuesday.
   1913 webster

   ash wednesday. see in the vocabulary.
      1913 webster
see also:
day woden wood ash wednesday 

[2] : WordNet (r) 2.0

wednesday
     n : the fourth day of the week; the third working day syn: wed
see also:
wed 

Wednesday >> W Words
Wednesday, definition of term: Wednesday
wednesday_pag1.html

Ash Wednesday >> A Words
Ash Wednesday, definition of term: Ash Wednesday
ash+wednesday_pag1.html