нея́сность

nounfeminineinanimateuncountablevery rarely used (#21245)noun in -ь

1.
lack of clarity, vagueness, obscurity
Меня́ смуща́ет нея́сность его отве́та.
The vagueness of his answer bothers me.
Usually uncountable: the property of not being clear.
2.
ambiguity, unclear point, uncertainty
В догово́ре оста́лось не́сколько нея́сностей.
A few ambiguities remain in the contract.
Countable, often plural: points that still need clarifying.

Examples

В его словах чувствовалась какая-то неясность
There was a certain obscurity in his words.
Неясность ситуации беспокоила всех присутствующих
The ambiguity of the situation worried everyone present.
В э́том зако́не полно нея́сностей.
That law is full of ambiguities.