The Collaborative International Dictionary of English v.0.48:

Stockinet \Stock`i*net"\, n.
   An elastic textile fabric imitating knitting, of which
   stockings, under-garments, etc., are made.
   [1913 Webster]

WordNet (r) 3.0 (2006):

stockinet
    n 1: knit used especially for infants' wear and undergarments
         [syn: stockinet, stockinette]