The Collaborative International Dictionary of English v.0.48:
Calceiform \Cal"ce*i*form`\ (k[a^]l"s[-e]*[i^]*f[^o]rm`), a. [L. calceus shoe + -form.] (Bot.) Shaped like a slipper, as one petal of the lady's-slipper; calceolate. [1913 Webster]WordNet (r) 3.0 (2006):
calceiform adj 1: of slipper-shaped blossoms; "the calceiform lip of certain orchids" [syn: calceolate, calceiform]