indeterminate
adjective uk/ˌɪn.dɪˈtɜː.mɪ.nət/ us/ˌɪn.dɪˈtɝː.mɪ.nət/
不确定的;不明确的
not measured, counted, or clearly known
An indeterminate number of workers have already been exposed to the danger. 一些工人已处在这种危险中，具体人数尚不清楚。
a man of indeterminate age 年龄不详的男子
Opposite: determinate