Lesson/ˈlesn/ Definition 1 of 3Pro Tip 1/3Learning Context Use 'lesson' when referring to a structured period dedicated to learning a skill or subject. I have a piano lesson every Thursday evening. Pro Tip 2/3Teaching Role 'Lessons' often imply that there is a teacher or instructor who guides the learning. My grandmother gives me cooking lessons on the weekend. Pro Tip 3/3Duration Variability A 'lesson' can be of varying lengths, typically from half an hour to several hours. Our art lessons last for two hours.