n. [ Cf. Feldspar. ] (Min.) A finegrained rock, flintlike in fracture, consisting essentially of orthoclase feldspar with occasional grains of quartz. [ 1913 Webster ]
a. relating to, composed of, or containing, felsite.
a. See Feldspathic. [ 1913 Webster ]
n. [ From G. feldstein, in analogy with E. felspar. ] (Min.) See Felsite. [ 1913 Webster ]