enrich
To improve something by adding things that make it better.
To enrich means to improve something by adding to it or making it better, fuller, or more valuable. When a teacher enriches her lessons by bringing in guest speakers or hands-on experiments, she's making the learning experience deeper and more interesting by going beyond textbook reading. When you enrich soil by mixing in compost, you're adding nutrients that help plants grow stronger.
The word often suggests adding something of quality or substance. A museum might enrich its collection by acquiring important artwork. Reading widely enriches your vocabulary and understanding of the world. Some foods are enriched with vitamins to make them more nutritious.
Enrichment activities at school, like robotics club or creative writing workshops, give you chances to develop skills and interests beyond regular classes. The word carries a sense of genuine improvement: you add something that makes the whole thing better, not merely more of the same.