忠心耿耿

    zhōngxīngěnggěng

    1. Idiomloyal and devoted (idiom); faithful and true

    这条狗忠心耿耿,一直守在门口。Zhè tiáo gǒu zhōngxīngěnggěng, yīzhí shǒu zài ménkǒu.The dog is loyal and devoted, always guarding the entrance.