What is the meaning of "abrupt" when describing an interaction?

The term "abrupt" in the context of describing an interaction refers to something that is sudden and unexpected, often characterized by a lack of preparation or a significant change that occurs without warning. For example, if someone leaves a conversation abruptly, it implies they did so without the usual social cues or gradual ending, which can leave the other person surprised or unsettled.

The other options do not capture the essence of "abrupt." Casual suggests a relaxed or informal tone, which contrasts with the suddenness implied by "abrupt." Smooth indicates a fluid or untroubled manner that does not align with the sharp inclination of suddenness. Instructive refers to providing information or direction, which does not relate to the nature of an interaction being sudden or unexpected. Thus, "sudden" is the accurate interpretation of "abrupt" in this context.