Definition of "papilla"

(anatomy) A nipple-like protuberance on a part or organ of the body.

1. A vascular process of connective tissue extending into and nourishing the root of a hair, feather, or developing tooth.  examples

2. Any of the vascular protuberances of the dermal layer of the skin extending into the epidermal layer and often containing tactile corpuscles.  examples

3. Any of the small protuberances on the upper surface of the tongue often containing taste buds.  examples

(botany) A small fleshy projection on a plant.  examples