IPA: /əˈseɪlənt/
KK: /əˈseɪlənt/
A person who attacks someone, often in a violent way.
The police arrested the assailant after the attack.
Assailant → It is formed from "assail" (from Old French *assailir*, meaning to attack) and "-ant" (a suffix used to indicate a person who performs an action). The word "assailant" refers to a person who attacks or assaults another.
Think of someone who is 'attacking' ('assail') — the '-ant' means a person who does that action. An assailant is a person who attacks.