The Collaborative International Dictionary of English v.0.48:

Slop \Slop\, n. [OE. sloppe a pool; akin to As. sloppe, slyppe,
   the sloppy droppings of a cow; cf. AS. sl?pan to slip, and E.
   slip, v.i. Cf. Cowslip.]
   1. Water or other liquid carelessly spilled or thrown aboyt,
      as upon a table or a floor; a puddle; a soiled spot.
      [1913 Webster]

   2. Mean and weak drink or liquid food; -- usually in the
      plural.
      [1913 Webster]

   3. pl. Dirty water; water in which anything has been washed
      or rinsed; water from wash-bowls, etc.
      [1913 Webster]

   Slop basin, or Slop bowl, a basin or bowl for holding
      slops, especially for receiving the rinsings of tea or
      coffee cups at the table.

   Slop molding (Brickmaking), a process of manufacture in
      which the brick is carried to the drying ground in a wet
      mold instead of on a pallet.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slop \Slop\, v. t. [imp. & p. p. Slopped; p. pr. & vb. n.
   Slopping.]
   1. To cause to overflow, as a liquid, by the motion of the
      vessel containing it; to spill.
      [1913 Webster]

   2. To spill liquid upon; to soil with a liquid spilled.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slop \Slop\, v. i.
   To overflow or be spilled as a liquid, by the motion of the
   vessel containing it; -- often with over.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slop \Slop\, n. [AS. slop a frock or over-garment, fr. sl?pan to
   slip, to slide; akin to Icel. sloppr a thin garment; cf. OHG.
   slouf a garment. Cf. Slip, v. i.]
   1. Any kind of outer garment made of linen or cotton, as a
      night dress, or a smock frock. [Obs.] --Halliwell.
      [1913 Webster]

   2. A loose lower garment; loose breeches; chiefly used in the
      plural. "A pair of slops." --Sir P. Sidney.
      [1913 Webster]

            There's a French salutation to your French slop.
                                                  --Shak.
      [1913 Webster]

   3. pl. Ready-made clothes; also, among seamen, clothing,
      bedding, and other furnishings.
      [1913 Webster]

WordNet (r) 3.0 (2006):

slop
    n 1: wet feed (especially for pigs) consisting of mostly kitchen
         waste mixed with water or skimmed or sour milk [syn:
         slop, slops, swill, pigswill, pigwash]
    2: deep soft mud in water or slush; "they waded through the
       slop" [syn: slop, mire]
    3: (usually plural) waste water from a kitchen or bathroom or
       chamber pot that has to be emptied by hand; "she carried out
       the sink slops"
    4: (usually plural) weak or watery unappetizing food or drink;
       "he lived on the thin slops that food kitchens provided"
    5: writing or music that is excessively sweet and sentimental
       [syn: treacle, mush, slop, glop]
    v 1: cause or allow (a liquid substance) to run or flow from a
         container; "spill the milk"; "splatter water" [syn:
         spill, slop, splatter]
    2: walk through mud or mire; "We had to splosh across the wet
       meadow" [syn: squelch, squish, splash, splosh,
       slosh, slop]
    3: ladle clumsily; "slop the food onto the plate"
    4: feed pigs [syn: slop, swill]

Moby Thesaurus II by Grady Ward, 1.0:

168 Moby Thesaurus words for "slop":
   asperge, bathos, bedew, bespatter, besprinkle, bilge, bilgewater,
   bleeding heart, bolt, bones, carrion, cascade, cataract, chaff,
   chuckhole, clay, cloyingness, cram, culm, dabble, damp, dampen,
   dash, deadwood, deluge, dew, dishwater, ditchwater, douche, douse,
   draff, dregs, dust, engulf, filings, flood, garbage, gash, glop,
   gobble, goo, gumbo, gunk, guzzle, hearts-and-flowers, hog wallow,
   hogwash, hose, hose down, humect, humectate, humidify, husks,
   ingurgitate, inundate, irrigate, leavings, lees, loblolly,
   maudlinness, mawkishness, mire, moisten, muck, muckhole, mud,
   mud puddle, mudhole, mush, mushiness, namby-pamby, namby-pambyism,
   namby-pambyness, nostalgia, nostomania, offal, offscourings, ooze,
   orts, overbrim, overflow, overrun, oversentimentalism,
   oversentimentality, overwhelm, paddle, pap, parings, plash,
   potsherds, pour out, pour over, puddle, rags, raspings, refuse,
   riffraff, romanticism, rubbish, run over, scourings, scrap iron,
   scraps, scum, scurf, sentiment, sentimentalism, sentimentality,
   sewage, sewerage, shards, shavings, slab, slack, slag, slime, slip,
   slob, slobber, slog, sloppiness, slops, slosh, slough, sludge,
   slush, soap opera, sob story, sparge, spatter, spill, spill out,
   spill over, splash, splatter, splosh, splurge, sponge, spray,
   sprinkle, spurtle, squab, squash, stodge, stubble, submerge, swamp,
   swash, sweep, sweepings, sweetness and light, swill, syringe,
   tares, tearjerker, toil, trash, trudge, wastage, waste,
   waste matter, wastepaper, water, weeds, wet, wet down, whelm,
   wolf



The Jargon File (version 4.4.7, 29 Dec 2003):

slop
 n.

    1. A one-sided fudge factor, that is, an allowance for error but in only
    one of two directions. For example, if you need a piece of wire 10 feet
    long and have to guess when you cut it, you make very sure to cut it too
    long, by a large amount if necessary, rather than too short by even a
    little bit, because you can always cut off the slop but you can't paste it
    back on again. When discrete quantities are involved, slop is often
    introduced to avoid the possibility of being on the losing side of a 
    fencepost error.

    2. The percentage of ?extra? code generated by a compiler over the size of
    equivalent assembler code produced by hand-hacking; i.e., the space (or
    maybe time) you lose because you didn't do it yourself. This number is
    often used as a measure of the goodness of a compiler; slop below 5% is
    very good, and 10% is usually acceptable. With modern compiler technology,
    esp. on RISC machines, the compiler's slop may actually be negative; that
    is, humans may be unable to generate code as good. This is one of the
    reasons assembler programming is no longer common.


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

slop

    1. A one-sided fudge factor, that is, an allowance
   for error but in only one of two directions.  For example, if
   you need a piece of wire 10 feet long and have to guess when
   you cut it, you make very sure to cut it too long, by a large
   amount if necessary, rather than too short by even a little
   bit, because you can always cut off the slop but you can't
   paste it back on again.  When discrete quantities are
   involved, slop is often introduced to avoid the possibility of
   being on the losing side of a fencepost error.

   2. The percentage of "extra" code generated by a compiler over
   the size of equivalent assembly code produced by
   hand-hacking; i.e. the space (or maybe time) you lose because
   you didn't do it yourself.  This number is often used as a
   measure of the quality of a compiler; slop below 5% is very
   good, and 10% is usually acceptable.  Modern compilers,
   especially on RISCs, may actually have *negative* slop; that
   is, they may generate better code than humans.  This is one of
   the reasons assembler programming is becoming less common.

   [Jargon File]

   (1995-05-28)