Entry 1 sense Webster, 1913 Phormium · Phor·mi·um · IPA /ˈfɔ(ɹ)ˌmiəm/ 01 n. A genus of liliaceous plants, consisting of one species (Phormium tenax). See Flax-plant. 1. A genus of liliaceous plants, consisting of one species (Phormium tenax). See Flax-plant.(Bot.) See: Flax-plant