The word 'taint' originates from the Latin verb 'tingere', meaning 'to dye, to moisten'. This root passed into Old French as 'teindre' (to dye) and its past participle 'teint' (dyed, colored), which was adopted into Middle English. The semantic evolution moved from the physical act of applying a color or stain to the more abstract concept of spoiling or corrupting something by introducing a negative element. Thus, the modern sense of a moral or physical contamination logically extends from this earlier notion of being stained or tinged with an unwanted quality.

The word 'taint' is a simplex word. It entered English as a whole unit from the Old French verb 'teint', meaning 'to dye, color, or tinge', which itself derived from the Latin 'tingere' (to dye, moisten). Its functional role is as a complete lexical root.