The Collaborative International Dictionary of English v.0.48:

Swap \Swap\, v. t. [imp. & p. p. Swapped; p. pr. & vb. n.
   Swapping.] [OE. swappen to strike; cf. E. to strike a
   bargain; perh. akin to E. sweep. Cf. Swap a blow, Swap,
   v. i.] [Written also swop.]
   1. To strike; -- with off. [Obs. or Prov. Eng.] "Swap off his
      head!" --Chaucer.
      [1913 Webster]

   2. To exchange (usually two things of the same kind); to
      swop. [Colloq.] --Miss Edgeworth.
      [1913 Webster]

Moby Thesaurus II by Grady Ward, 1.0:

34 Moby Thesaurus words for "swapping":
   agency, backscratching, barter, bartering, brokerage,
   buying and selling, colossal, dealing, doing business, enormous,
   even trade, exchange, giant, gigantic, give-and-take,
   horse trading, immense, interchange, jobbing, jumbo, logrolling,
   mammoth, merchandising, pork barrel, retailing, swap, switch,
   trade, trading, trafficking, tremendous, wheeling and dealing,
   wholesaling, whopping



The Free On-line Dictionary of Computing (30 December 2018):

swap
swapped in
swapped out
swapping

    To move a program from fast-access memory
   to a slow-access memory ("swap out"), or vice versa ("swap
   in").  The term often refers specifically to the use of a
   hard disk (or a swap file) as virtual memory or "swap
   space".

   When a program is to be executed, possibly as determined by a
   scheduler, it is swapped into core for processing; when it
   can no longer continue executing for some reason, or the
   scheduler decides its time slice has expired, it is swapped
   out again.

   This contrasts with "paging" systems in which only parts of a
   program's memory is transfered.

   [Jargon File]

   (1996-11-22)