astrophysics /ˌæstrəˈfɪzɪks/ noun Learner's definition of ASTROPHYSICS
[noncount]
: the scientific study of the physical and chemical properties and structures of stars, planets, and other objects in outer space天体物理学
— astrophysical
/ˌæstrəˈfɪzɪkəl/ adjective — astrophysicist
/ˌæstrəˈfɪzəsɪst/ noun, plural astrophysicists [count]