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

undated \un"dated\ u^n"daslte^d, a. l. undatus, p. p.
   of undare to rise in waves, to wave, to undulate, fr. unda a
   wave. see undulate. bot.
   rising and falling in waves toward the margin, as a leaf;
   waved.
   1913 webster
see also:
undulate 

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

undated \undat"ed\ u^nd=at"e^d, a. pref. un- not +
   dated.
   not dated; having no date; of unknown age; as, an undated
   letter.
   1913 webster

[3] : WordNet (r) 2.0

undated
     adj : not bearing a date; "a dateless letter" syn: dateless
see also:
dateless 

Undated >> U Words
Undated, definition of term: Undated
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