Meaning of “highly” - Learner’s Dictionary

highly

adverb us uk /ˈhaɪli/
VERY

B2 very or to a large degree:

It is highly unlikely that they will succeed.

More examples

HIGH LEVEL

B2 at a high level:

a highly paid worker
to speak/think highly of sb/sth

to have or express a very good opinion of someone or something:

The course is very highly thought of.

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