How do you motivate a smart lazy child?

Taking an interest and offering encouragement and support is one of the best ways to motivate an unmotivated child. By keeping the dialog open, you'll get an opportunity to find out what the real issue is because it's seldom a child that's genuinely just lazy.

Is it OK to call your child lazy?

Generally speaking, it's not okay to call your child lazy, even if the outward appearance is such. A child could be struggling with depression, being overworked, or just exhausted. Calling a child lazy questions their work and character while very seldom getting to a root cause.