noun

• (uncountable) A mixture of mineral particles and organic material, used to support plant growth.
  "We bought a bag of soil for the houseplants."
• (uncountable) The unconsolidated mineral or organic material on the immediate surface of the earth that serves as a natural medium for the growth of land plants.
• (uncountable) The unconsolidated mineral or organic matter on the surface of the earth that has been subjected to and shows effects of genetic and environmental factors of: climate (including water and temperature effects), and macro- and microorganisms, conditioned by relief, acting on parent material over a period of time. A product-soil differs from the material from which it is derived in many physical, chemical, biological, and morphological properties and characteristics.

verb

• (transitive) To make dirty.
  "[…]Bad Fruit of Knowledge, if this be to know, / Which leaves us naked thus, of Honour void, / Of innocence, of Faith, of Puritie, / Our wonted Ornaments now ſoild and ſtaind, / And in our Faces evident the ſignes / Of foul concupiſcence ; whence eveil ſtore ; / Even ſhame, the laſt of evils ; of the firſt / Be ſure then."
• (intransitive) To become dirty or soiled.
  "Light colours soil sooner than dark ones."
• (transitive, figurative) To stain or mar, as with infamy or disgrace; to tarnish; to sully.
  "[…]They clip vs drunkards, and with Swiniſh phraſe / Soyle our addition, and indeede it takes / From our atchieuements, though perform’d at height / The pith and marrow of our attribute[…]"
• (reflexive) To dirty one's clothing by accidentally defecating while clothed.
  "The child was so scared she soiled herself."

noun

• (uncountable, euphemistic) Faeces or urine etc. when found on clothes.
• (countable, medicine) A bag containing soiled items.