A threat of harm refers to a situation where an individual is coerced or compelled to act against their will due to the fear of impending violence or injury. This concept is essential in understanding duress, as it highlights how a person may feel pressured to commit an act they would not normally undertake, often resulting from intimidation or threats made by another party. Recognizing the role of such threats in legal contexts is crucial, especially when determining the validity of defenses related to coercion.