un·dat·ed
adjective/ˌʌnˈdeɪtɪd/
/ˌʌnˈdeɪtɪd/
- without a date written or printed on it
未注日期的 - an undated letter
一封没写日期的信
- an undated letter
- of which the date is not known
日期不明的；时间不详的 - undated archaeological remains
时间未确定的考古遗迹
compare dated - undated archaeological remains