IPA: /əˈsweɪsɪv/
KK: /ə'sweɪsɪv/
Having a calming or soothing effect; intended to comfort or alleviate distress.
The therapist used an assuasive tone to help the anxious patient relax.
Assuasive is formed from "assuadere" (meaning to soothe or calm) and the suffix "-ive" (meaning having the nature of). The word describes something that has the nature of soothing or calming.
Think of something that 'soothes' ('assuadere') — that's why 'assuasive' means having a calming effect.