Answer:
Depending on the context in which it is used, laggy may be correctly used as the opposite of smooth.
Step-by-step explanation:
Smooth could be explained as having a fluid, regular appearance or behavior. Such as having a smooth surface which is devoid of bumps or free of itch. To relate laggy to mean the opposite of smooth, we may need to refer to context where we are evaluating the performance of a machine or system. A smooth performance would mean one which is responsive, and controls are effected almost immediately. While a laggy performance means a situation whereby system is late to respond.