The Collaborative International Dictionary of English v.0.48:
Ingrown \In"grown`\, a. Having grown or appearing to grow into some other substance, especially a fingernail or toenail growing into the adjacent flesh. [1913 Webster +PJC] Ingrown toenail, a toenail whose edges have becoming imbedded in the adjacent flesh. [1913 Webster +PJC]WordNet (r) 3.0 (2006):
ingrown adj 1: growing abnormally into the flesh; "an ingrown toenail" [syn: ingrowing, ingrown]