substitute

(noun) a person or thing that takes or can take the place of another. Synonyms: replacement.

(noun) an athlete who plays only when a starter on the team is replaced. Synonyms: reserve, second-stringer.

(noun) someone who takes the place of another (as when things get dangerous or difficult). Synonyms: stand-in, relief, reliever, backup, backup man, fill-in. Examples: "The star had a stand-in for dangerous scenes." "We need extra employees for summer fill-ins."

(verb) put in the place of another; switch seemingly equivalent items. Synonyms: replace, interchange, exchange. Examples: "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."

(verb) be a substitute. Synonyms: sub, stand in, fill in. Examples: "The young teacher had to substitute for the sick colleague." "The skim milk substitutes for cream--we are on a strict diet."

(verb) act as a substitute. Synonyms: deputize, deputise, step in. Example: "She stood in for the soprano who suffered from a cold."

(adj) capable of substituting in any of several positions on a team. Synonyms: utility(prenominal), substitute(prenominal). Example: "A utility infielder."

(adj) serving or used in place of another. Synonyms: alternate, alternative. Example: "An alternative plan."

(adj) artificial and inferior. Synonyms: ersatz. Examples: "Ersatz coffee." "Substitute coffee."