Dictionary > English Dictionary > Definition, synonym and antonym of his back is up
Meaning of his back is up by Wiktionary Dictionary

his back is up

    Alternative forms

    he's got his back up


    his back is up

    1. ( idiomatic, obsolete, slang ) he is offended or angry; an expression or idea taken from a cat; that animal, when angry, always raising its back. An allusion also sometimes used to jeer a crooked man;
      So, Sir, I see somebody has offended you, for your back is up .