Wordnet 3.0
NOUN (1)
1. 
 something that grows inward; 
The Collaborative International Dictionary of English v.0.48:
Ingrowth \In"growth`\, n.
   A growth or development inward. --J. LeConte.
   [1913 Webster]
WordNet (r) 3.0 (2006):
ingrowth
    n 1: something that grows inward