late Middle English: from Anglo-Norman French, perhaps representing Latin solium 'seat', by association with solum 'ground'Middle English (as a verb): from Old French soiller, based on Latin sucula, diminutive of sus 'pig'. The earliest use of the noun (late Middle English) was 'muddy wallow for wild boar'; current noun senses date from the early 16th centearly 17th cent.: perhaps from soil