tubercle

(to͞oˈbər-kəl, tyo͞oˈ-)

1. A small rounded projecting part or outgrowth, such as a wartlike excrescence on the roots of some leguminous plants or a knoblike process in the skin or on a bone.
2. Pathology A nodule or swelling, especially a mass of lymphocytes and epithelioid cells forming the characteristic lesion of tuberculosis.