substitute

SUBSTITUTE noun

[ C ] uk/ˈsʌbstɪtjuːt/ us
B2 someone or something that is used instead of another person or thing

заместитель, замена
Margarine can be used as a substitute for butter. a substitute teacher
substitute verb uk/ˈsʌbstɪtjuːt/ us
B2 [ T ] to use someone or something instead of another person or thing

заменять
You can substitute pasta for the rice, if you prefer.  substitute for sb
to do someone's job because they are not there

замещать кого-либо
I'm substituting for her while she's on holiday.
substitution noun [ C,U ] uk/ˌsʌbstɪˈtjuːʃən/ us

замена