noun, noun or participle which takes 'suru', transitive verb
protecting (someone); defending; standing up for
Refers to actively shielding or defending a person from criticism, blame, or harm, often with a nuance of partiality or favoritism. Can be used as a noun or with する as a transitive verb.
彼はいつも弟を庇い立てする。
He always stands up for his younger brother.
上司の庇い立て
Without his boss's protection, he would have been fired long ago.