[1] : The Collaborative International Dictionary of English v.0.48

sliding \slid"ing\, a.
   1. that slides or slips; gliding; moving smoothly.
      1913 webster

   2. slippery; elusory. obs.
      1913 webster

            that sliding science hath me made so bare.
                                                  --chaucer.
      1913 webster

   sliding friction mech., the resistance one body meets
      with in sliding along the surface of another, as
      distinguished from rolling friction.

   sliding gunter naut., a topmast arranged with metallic
      fittings so as to be hoisted and lowered by means of
      halyards.

   sliding keel naut, a movable keel, similar to a
      centeboard.

   sliding pair. mech. see the note under pair, n., 7.

   sliding rule. same as slide rule, under slide, n.

   sliding scale.
      a a scale for raising or lowering imposts in proportion
          to the fall or rise of prices.
      b a variable scale of wages or of prices.
      c a slide rule.

   sliding ways naut., the timber guides used in launching a
      vessel.
      1913 webster
see also:
sliding friction sliding gunter sliding keel sliding pair pair sliding rule 
slide rule slide sliding scale sliding ways 

[2] : The Collaborative International Dictionary of English v.0.48

pair \pair\ p^ar, n. f. paire, ll. paria, l. paria, pl. of
   par pair, fr. par, adj., equal. cf. apparel, par
   equality, peer an equal.
   1913 webster
   1. a number of things resembling one another, or belonging
      together; a set; as, a pair or flight of stairs. "a pair
      of beads." --chaucer. --beau.  fl. "four pair of stairs."
      --macaulay.

   note: now mostly or quite disused.
         1913 webster

               two crowns in my pocket, two pair of cards.
                                                  --beau.  fl.
         1913 webster

   2. two things of a kind, similar in form, suited to each
      other, and intended to be used together; as, a pair of
      gloves or stockings; a pair of shoes.
      1913 webster

   3. two of a sort; a span; a yoke; a couple; a brace; as, a
      pair of horses; a pair of oxen.
      1913 webster

   4. a married couple; a man and wife. "a happy pair."
      --dryden. "the hapless pair." --milton.
      1913 webster

   5. a single thing, composed of two pieces fitted to each
      other and used together; as, a pair of scissors; a pair of
      pants; a pair of tongs; a pair of bellows.
      1913 webster

   6. two members of opposite parties or opinion, as in a
      parliamentary body, who mutually agree not to vote on a
      given question in order, for example, to allow the
      members to be absent during the vote without affecting the
      outcome of the vote, or on issues of a party nature
      during a specified time; as, there were two pairs on the
      final vote. parliamentary cant

   note: a member who is thus paired with one who would have
         voted oppositely is said to be paired for or paired
         against a measure, depending on the member's position.
         1913 webster +pjc

   7. kinematics in a mechanism, two elements, or bodies,
      which are so applied to each other as to mutually
      constrain relative motion.
      1913 webster

   note: pairs are named in accordance with the kind of motion
         they permit; thus, a journal and its bearing form a
         turning pair, a cylinder and its piston a sliding
         pair, a screw and its nut a twisting pair, etc. any
         pair in which the constraining contact is along lines
         or at points only as a cam and roller acting
         together, is designated a higher pair; any pair
         having constraining surfaces which fit each other as a
         cylindrical pin and eye, a screw and its nut, etc., is
         called a lower pair.
         1913 webster

   pair royal pl. pairs royal three things of a sort; --
      used especially of playing cards in some games, as
      cribbage; as three kings, three "eight spots" etc. four of
      a kind are called a double pair royal. "something in his
      face gave me as much pleasure as a pair royal of naturals
      in my own hand." --goldsmith. "that great pair royal of
      adamantine sisters the fates." --quarles. written
      corruptly parial and prial.
      1913 webster

   syn: pair, flight, set.

   usage: originally, pair was not confined to two things, but
          was applied to any number of equal things pares,
          that go together. ben jonson speaks of a pair set of
          chessmen; also, he and lord bacon speak of a pair
          pack of cards. a "pair of stairs" is still in
          popular use, as well as the later expression, "flight
          of stairs."
          1913 webster
see also:
apparel par peer turning pair sliding pair twisting pair 
higher pair lower pair pair royal pairs royal parial 
prial pair flight set 

Pair >> P Words
Pair, definition of term: Pair
pair_pag1.html

Pair Off >> P Words
Pair Off, definition of term: Pair Off
pair+off_pag1.html

Au Pair >> A Words
Au Pair, definition of term: Au Pair
au+pair_pag1.html