nosedive

US /ˈnoʊz.daɪv/
UK /ˈnoʊz.daɪv/
1.

lao xuống

a fast and sudden fall to the ground with the front pointing down:

:
The plane roared overhead and went into a nosedive.
1.

lao xuống

to suddenly fall to the ground with the front pointing down:

:
Spectators in the crowd watched in horror as the plane nosedived.