Meaning of “dive” - Learner’s Dictionary

dive

noun [ C ] uk us /daɪv/
JUMP

B2 a jump into water with your arms and head going in first

MOVEMENT
VALUE

a sudden reduction in the value or price of something:

Share prices took a dive today.
PLACE informal

a place such as a bar that is considered to be dirty or of low quality

(Definition of “dive noun” from the Cambridge Learner’s Dictionary © Cambridge University Press)