Meaning of “defensive” - Learner’s Dictionary

defensive

adjective uk us /dɪˈfensɪv/
CRITICISM

quick to protect yourself from being criticized:

He's very defensive about his weight.
SPORT mainly US

A defensive player in a sports team tries to stop the other team scoring points.

ATTACK

done or used to protect someone or something from attack

defensively adverb

"I wasn't even there," she said defensively.

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