Definition from Design For Health
“Human-centered design (HCD) is the process of integrating human perspectives in all steps of the problem-solving process. The process aims to better understand an issue from the human perspective and focuses on how it looks and feels to users and stakeholders within their environment and context.”
Going further
I've curated 400+ definitions just like this one in a tiny dictionary. In this glossary you can easily access, search and understand 400+ terms that service designers and other innovators use.