Psychic assault is a term used by academic legal writers as a synonym for assault

Assault

In law, assault is a crime causing a victim to fear violence. The term is often confused with battery, which involves physical contact. The specific meaning of assault varies between countries, but can refer to an act that causes another to apprehend immediate and personal violence, or in the more...

 (or common assault

Common assault

Common assault was an offence under the common law of England, and has been held now to be a statutory offence in England and Wales. It is committed by a person who causes another person to apprehend the immediate use of unlawful violence by the defendant. It was thought to include battery...

) in order to distinguish that offence from the related crime of battery

Battery (crime)

Battery is a criminal offense involving unlawful physical contact, distinct from assault which is the fear of such contact.In the United States, criminal battery, or simply battery, is the use of force against another, resulting in harmful or offensive contact...

 and so avoid confusion. The need for this term arises from the fact that the word assault is frequently used to refer collectively both to that offence and to battery.

The word 'psychic' is used to denote the fact that the actus reus

Actus reus

Actus reus, sometimes called the external element or the objective element of a crime, is the Latin term for the "guilty act" which, when proved beyond a reasonable doubt in combination with the mens rea, "guilty mind", produces criminal liability in the common law-based criminal law jurisdictions...

of the offence that is correctly described as assault consists of affecting the mind of the other person (whereas battery consists of the application of force).