1. A way of speaking, writing, or acting that is not easy to understand; lack of clarity in communication or behavior
He explained the concept in an unclear manner, leaving everyone confused.
Ele explicou o conceito de maneira pouco clara, deixando todos confusos.
2. Ambiguous or vague expression that does not convey intended meaning distinctly
The instructions were written in an unclear manner.
As instruções foram escritas de forma ambígua.