(mineralogy) Clear quartz crystal containing coloured filaments caused by impurities. Particular kinds are sometimes known as Venus’s hair stone or Thetis’s hair stone.

A theorem postulating that all black hole solutions of the Einstein-Maxwell equations in general relativity can be completely characterized by only three externally observable classical parameters: mass, electric charge, and angular momentum.

Briza media, a variety of grass.

Any of various seals which have coarse hair rather than fur / especially the true seals or earless seals of family Phocidae.

plural of hair-dryer

Alternative spelling of hair dryer; alternative spelling of hairdryer

Alternative spelling of hair-salt

(mineralogy, dated) A habit of epsomite which occurs as silky, hair-like fibers.

Agrostis scabra, a bunchgrass. / Several species of Aira. / Species of junegrass (Koeleria). / Several species of tussock grass (Deschampsia).

(biology) The rhizoid of a vascular plant; a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root.