undated

/AH0 N D EY1 T IH0 D/
adjective
  1. 1

    Not marked with a date.

  2. 2

    Of a style that will not go out of fashion; a classic.

adjective
  1. 1

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

Source: https://en.wiktionary.org/wiki/undated