Webster's Revised Unabridged Dictionary · 1913

Undated

Undated (un"da*ted) , adjective

[Latin undatus, past participle of undare to rise in waves, to wave, to undulate, from unda a wave. See Undulate.]

(Botany) Rising and falling in waves toward the margin, as a leaf; waved.

Undated (un*dāt"ed) , adjective

[Prefix un- not + dated.]

Not dated; having no date; of unknown age; as, an undated letter.