1
general::
Phrase(s): substitute for someone or something
to serve as a replacement for someone or something. • I have to substitute for Roger at work this weekend. • Do you think that this will substitute for the one you wanted?, Phrase(s): substitute someone for someone else [and] substitute something for something else
to exchange someone or something for someone or something else; to replace someone or something with someone or something else. • Shall I substitute Fred for Mary in the front office? • Please substitute fish for beef on my dinner order.
McGrawhill's American Idioms And Phrasal Verbs