The Collaborative International Dictionary of English v.0.48:

Pat \Pat\, n.
   1. A light, quik blow or stroke with the fingers or hand; a
      tap.
      [1913 Webster]

   2. A small mass, as of butter, shaped by pats.
      [1913 Webster]

            It looked like a tessellated work of pats of butter.
                                                  --Dickens.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pat \Pat\, a. [Cf. pat a light blow, D. te pas convenient, pat,
   where pas is fr. F. passer to pass.]
   Exactly suitable; fit; convenient; timely. "Pat allusion."
   --Barrow.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pat \Pat\, adv.
   In a pat manner.
   [1913 Webster]

         I foresaw then 't would come in pat hereafter.
                                                  --Sterne.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Pat \Pat\, v. t. [imp. & p. p. Patted; p. pr. & vb. n.
   Patting.] [Cf. G. patschen, Prov. G. patzen, to strike,
   tap.]
   To strike gently with the fingers or hand; to stroke lightly;
   to tap; as, to pat a dog.
   [1913 Webster]

         Gay pats my shoulder, and you vanish quite. --Pope.
   [1913 Webster]

WordNet (r) 3.0 (2006):

pat
    adv 1: completely or perfectly; "he has the lesson pat"; "had
           the system down pat"
    adj 1: having only superficial plausibility; "glib promises"; "a
           slick commercial" [syn: glib, pat, slick]
    2: exactly suited to the occasion; "a pat reply"
    n 1: the sound made by a gentle blow [syn: pat, rap, tap]
    2: a light touch or stroke [syn: tap, pat, dab]
    v 1: pat or squeeze fondly or playfully, especially under the
         chin [syn: chuck, pat]
    2: hit lightly; "pat him on the shoulder" [syn: dab, pat]

Moby Thesaurus II by Grady Ward, 1.0:

133 Moby Thesaurus words for "pat":
   a propos, ad rem, adamant, adamantine, adapted, applicable,
   apposite, appreciated, apprehended, appropriate, apropos, apt,
   artful endearments, ascertained, at a standstill, batch, beak,
   becoming, befitting, blandishments, block, brush, bulk, bump, bunt,
   caress, chink, chuck, chunk, click, clink, clod, clop, clump,
   clunk, cocker, coddle, comprehended, conceived, cosset, crump, dab,
   dandle, discerned, dovetailing, down pat, dull thud, endearment,
   felicitous, fillip, firm, fit, fitted, fitting, flick, flip, flirt,
   flump, fondle, frozen, geared, gob, grasped, graze, happy,
   honeyed words, hunk, immobile, immotile, immotive, immovable,
   inflexible, irremovable, just right, known, likely, loaf, lump,
   mass, meshing, nugget, on the button, opportune, pad, patter, peck,
   perceived, pet, pick, pitapat, pitter-patter, plump, plunk, pop,
   prehended, qualified, quantity, rap, realized, recognized,
   relevant, right, rigid, seasonable, seized, snap, soft words,
   sortable, standpat, stationary, suitable, suited, suiting,
   sweet nothings, sweet talk, tailored, tap, thud, thump, tick,
   tickle, tinkle, tip, to the point, to the purpose, touch, tunk,
   understood, unmovable, unmoving, unyielding, wad, whisk



V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

PAT
       Performance Acceleration Technique (Intel, MCH)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

PAT
       Port and Address Translation (IOS, Cisco, LAN, IP)


V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016):

PAT
       Program Association Table (DVB)


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

PAT

   1.  Personalized Array Translator.

   2.  Port Address Translation.

   (1998-05-09)