*chem·is·try/`kɛmɪstrɪ; ˈkemɪstri/ n [U] 1 the science of studying chemicals and what happens to them when they change or combine with each other 化学 2 the way substances combine in a process, thing, person etc 〔过程、物质、人等的〕化学组成; 化学变化: This drug causes changes to the body's chemistry. 这种药引起身体化学作用的变化。