To regard someone or something as untrustworthy.

किसी को या किसी चीज़ को अविश्वासी मानना।

English Usage: She mistrusted his intentions after his unexpected behavior.

Hindi Usage: उसकी अप्रत्याशित हरकत के बाद वो उसकी नीयत को अविश्वासी मानने लगी।