premature

¹pre·ma·ture

adj
\-mə-ˈt(y)u̇(ə)r, -ˈchu̇(ə)r, chiefly British ˌprem-ə-\

Definition of PREMATURE

: happening, arriving, existing, or performed before the proper, usual, or intended time; especially : born after a gestation period of less than 37 weeks <premature babies>

—pre·ma·ture·ly adverb