Assault is the criminal offence of intentionally applying force to another person without their consent, threatening to apply force if the recipient reasonably believes the person can carry out the threat, or bothering another person while openly wearing or carrying a weapon (or imitation of a weapon).
Assault also refers to a civil tort. In civil cases, assault means someone threatening to physically contact another without their consent. The recipient must have a reasonable belief that the harm was imminent. If the aggressor physically contacts the recipients, that is the civil tort of battery.