What is the meaning of Trời?

the sky

weather

a generic deification of the sky that is said to be able to grant "natural gifts" (talent, good weather, etc.) and deal heavenly "punishments" (storms, lightning, etc.); he may be conflated with the Ngọc Hoàng (Jade Emperor) borrowed from Chinese myths; the heavenly lord; compare Chinese 老天 (lǎotiān, literally old heaven)

wild

Used after ngày, tháng, or năm to emphasize a lengthy duration

good Lord!

Source: wiktionary.org