heliozoa
- n mostly freshwater protozoa
- n protozoa with spherical bodies and stiff radiating pseudopods
heliozoan
- n protozoa with spherical bodies and stiff radiating pseudopods
helipterum
- n genus of South African and Australian herbs or shrubs grown as everlastings; the various Helipterum species are currently in process of being assigned to other genera especially genera Pteropogon and Hyalosperma
helipterum manglesii
- n Australian annual everlasting having light pink nodding flower heads; sometimes placed in genus Helipterum
helium
- n a very light colorless element that is one of the six inert gasses; the most difficult gas to liquefy; occurs in economically extractable amounts in certain natural gases (as those found in Texas and Kansas)
helix
- n a curve that lies on the surface of a cylinder or cone and cuts the element at a constant angle
- n a structure consisting of something wound in a continuous series of loops
- n type genus of the family Helicidae
helix angle
- n the constant angle at which a helix cuts the elements of a cylinder or cone
helix aspersa
- n serious garden pest having a brown shell with paler zigzag markings; nearly cosmopolitan in distribution