definition of
substitute

[1] #1 substitute v. [replace, interchange, exchange] put in the place of another; switch seemingly equivalent items; "the con artist replaced the original with a fake Rembrandt"; "substitute regular milk with fat-free milk"; "synonyms can be interchanged without a changing the context's meaning". wn

[2] #2 substitute n. [replacement] a person or thing that takes or can take the place of another. wn

[3] #3 substitute v. [sub, stand in, fill in] be a substitute; "The young teacher had to substitute for the sick colleague"; "The skim milk substitutes for cream--we are on a strict diet". wn

[4] #4 substitute n. [reserve, second-stringer] an athlete who plays only when a starter on the team is replaced. wn

[5] #5 substitute n. [stand-in, relief, reliever, backup, backup man, fill-in] someone who takes the place of another (as when things get dangerous or difficult); "the star had a stand-in for dangerous scenes"; "we need extra employees for summer fill-ins". wn