What does "slop" mean?

Additional senses

1. 2.pl. Dirty water; water in which anything has been washed or rinsed; water from wash-bowls, etc. 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.
2. 3.To cause to overflow, as a liquid, by the motion of the vessel containing it; to spill.
3. 4.To spill liquid upon; to soil with a liquid spilled.
4. 5.To overflow or be spilled as a liquid, by the motion of the vessel containing it; -- often with over.
5. 6.Any kind of outer garment made of linen or cotton, as a night dress, or a smock frock. [Obs.] Halliwell.
6. 7.A loose lower garment; loose breeches; chiefly used in the plural. "A pair of slops." Sir P. Sidney. There's a French salutation to your French slop. Shak.
7. 8.pl. Ready-made clothes; also, among seamen, clothing, bedding, and other furnishings.