1
general::
Phrase(s): stand up to someone or something
to take a stand against someone or something; to hold one’s ground or principles in the face of a challenge by someone or something. • He is a tough customer, and you have to learn to stand up to him. • Can the witness stand up to questioning by the prosecution?
McGrawhill's American Idioms And Phrasal Verbs
2
general::
Confront fearlessly, oppose boldly, as in You've got to stand up to the boss if you want him to respect you. [Early 1600s]
American Heritage Idioms