A replacement or stand-in for something that achieves a similar result or purpose.
A player who is available to replace another if the need arises, and who may or may not actually do so.
One who enlists for military service in the place of a conscript.
To remove (a player) from the field of play and bring on another in his place.
To serve as a replacement (for someone or something).
To use in place of something else, with the same function.
To use X in place of Y.
To use Y in place of X; to replace X with Y.
Anything that is swapped out for another; an exchange.
A pre-prepared food item used in place of an unfinished food item in order to cut down the overall preparation time during filming.
To exchange (something) for (something else). (usually followed by with or for)
To transfer (memory contents) into a swap file.
To exchange (something or someone) for an unused (or less-used) equivalent.