未知数wèizhīshù 1.代数式或方程中,数值需要经过运算才能确定的数。如3x＋6=27中, x是未知数。{unknown number, a number in algebraic expression or equation that should be decided through calculation, such as ‘x’ in the equation 3x＋6=27} 2.〈比喻fig.〉还不知道的事情{unknown; uncertain}: 能否成功,还是个～。{It's still uncertain whether it will be a success or not.}