indefinite 不确定的
eg：She will be away for the indefinite future.
她将离开一段时间,期限不定
unspecified未指明的
eg：The story takes place at an unspecified date.x05
故事发生的日期不明
unidentified 身份不明的
eg：The previously unidentified objects have now been definitely ascertained as being satellites.
原来所说的不明飞行物现在已证实是卫星
懂了没,新年快乐哦,