Meaning of “reply” - Learner’s Dictionary

reply

verb [ I, T ] us uk /rɪˈplaɪ/
"I don't believe a word you're saying," she replied bluntly.Make sure you reply to the invitation.David never replied to my letter.When are you going to reply to his letter?We will reply to all enquiries within 48 hours.

B1 to answer:

"I don't understand," she replied.
He didn't reply to my email.
[ + that ] Henry replied that he had no idea what I was talking about.

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