Meaning of “thank you” - Learner’s Dictionary

thank you

exclamation us uk

A1 used to tell someone that you are grateful because they have given you something or done something for you:

Thank you very much for the birthday card.
"Here's the money I promised you." "Thank you."

More examples

thank you/no, thank you

A2 used to accept or refuse someone's offer:

"Would you like something to eat?" "No, thank you."

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