n.

1. 不確定；不確信；易變；不可靠[U]
   realize the uncertainty of life

   意識到人生變幻無常

   John was depressed by the uncertainty of his position and duty.

   不確定的職位和職能使約翰感到沮喪。

2. 不確定的事物；難以預料的事物[C][P1]
   Do what you can and don't worry about uncertainties.

   盡力做你所能做的事情，不要為難以預料的事物而煩惱。