The Collaborative International Dictionary
astrochemical
astrochemistry \astrochemistry\ n. the branch of science involving astronomy and chemistry which studies the chemical composition, chemical reactions, and evolution of matter in outer space. -- as`tro*chem"ic*al, a. -- as`tro*chem"ic*al*ly, adv.
Wiktionary
astrochemical
a. Of or pertaining to astrochemistry