To be honest, I can't grasp the meaning of the word "defensive". According to a dictionary, they define about "defensive" that behaving in a way that shows that you feel that people are criticizing you. the example sentences of the word are below.
Don't ask him about his plans—he just gets defensive.
He is extremely defensive about his work
Whenever anyone mentions women's rights, he gets rather defensive.
I conceive that "defensive is a little similar to "rigid".
What do you think of that? Does anyone who can explain the meaning of the word in detail like feelings?