Which term refers to knowingly detaining another without legal justification?

The term that best describes the act of knowingly detaining another person without legal justification is unlawful restraint. This legal terminology specifically pertains to situations in which an individual is held against their will without proper legal authority or justification. Unlawful restraint can occur in various contexts and does not necessarily imply the use of force or aggression; it merely requires the absence of legal justification for the detention.

In contrast, other terms like kidnapping typically imply the intent to physically move the victim or hold them for ransom, which involves additional elements such as abduction. Forcible detention usually connotes a more aggressive or violent method of confinement, emphasizing the use of force in the detention process. Therefore, unlawful restraint succinctly captures the essence of detaining someone without the appropriate legal grounds, making it the most accurate choice in this context.