Define development: the act, process, or result of developing; the state of being developed — development in a sentence Development definition, the act or process of developing; growth; progress: child development; economic development. See more. Abstracts archived from 1983, with full text available by subscription. Includes keyword search, subcribing details and other titles from The Company of Biologists. Synonyms for development at Thesaurus.com with free online thesaurus, antonyms, and definitions. Dictionary and Word of the Day. Land use. Land development; Green development, a concept that includes consideration of community-wide or regional environmental implications; Land development bank.