Meaning of “heavily” - Learner’s Dictionary

heavily

adverb uk us /ˈhevɪli/
A LOT

B1 a lot or to a great degree:

She's heavily involved in politics.
drink/smoke heavily

to drink/smoke a lot

rain/snow heavily

to rain/snow a lot

FORCE

using a lot of force:

to breathe heavily

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