Meaning of “secret” - Learner’s Dictionary

secret

adjective uk us /ˈsiːkrət/

B1 If something is secret, other people are not allowed to know about it:

a secret affair/meeting
I'll tell you but you must keep it secret.
secret admirer/drinker, etc

someone who does something or feels something without telling other people about it

secretly adverb

B1

He secretly taped their conversation.
→ See also top-secret

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