To exchange two things, with both parties giving one thing and taking another thing.
To move backwards and forwards, like a piston.
To give something else in response (where the "thing" may also be abstract, a feeling or action) To make a reciprocal gift.
To counter, retort or retaliate.
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.
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.