The act of instilling; also, that which is instilled.
1. (Anat.) The protuberance through which milk is drawn from the breast or mamma; the mammilla; a teat; a pap. 2. The orifice at which any animal liquid, as the oil from an oil bag, is discharged. [R.] Derham. 3. Any small projection or article in which there is an orifice for discharging a fluid, or for other purposes; as, the nipple of...