dye / dī/ • n. a natural or synthetic substance used to add a color to or change the color of something.• v. (dyed, dye·ing) [tr.] add a color to or change the color of (something) by soaking it in a solution impregnated with a dye: I dyed my hair red ∎  [intr.] take color well or badly during such a process: it's good material—it should dye well.PHRASES: dyed in the wool unchanging in a particular belief or opinion; inveterate: she's a dyed-in-the-wool conservative.DERIVATIVES: dye·a·ble adj.dy·er n.

dye Substance, natural or synthetic, used to impart colour to various substances. Natural dyes have mostly been replaced by synthetic dyes, many derived from coal tar. Dyes are classified according to their application: direct dyes, such as sulphur and vat dyes, can be applied directly to fabric because they bind to the fibres. Indirect dyes, such as ingrain and mordant dyes, require a secondary process to fix the dye.

dye vb. OE. dēagian, of unkn. orig. Not recorded again till XIV, though the agent-nouns dyer, dyester are recorded from XIII.
So dye sb. OE. dēag, dēah, rare ME. dēag; the present word is a new formation on the vb. (XVI). The words are peculiarly Eng.