To think, represent, or speak of as small or unimportant
"Just make sure you don't order her around or belittle her," Katie ordered.
"You know," she continued as she scooped grain into a stanchion, "it really galls me that Josh is always encouraging Lori with her work, but he never misses an opportunity to belittle mine.
It is against the rules for students to belittle each other.
Gail imagined that there was an organized conspiracy to belittle his learning and professional success, and there was a standing quarrel between him and his literary opponents.
A good way to hurt someone's confidence is to belittle their hard work.