(mineralogy) A trigonal-rhombohedral mineral containing magnesium, oxygen, and titanium.

(mineralogy) A triclinic-pinacoidal mineral containing arsenic, hydrogen, manganese, and oxygen.

A vulture.

(chemistry) Humin.

plural of Geissler tube

An early gas discharge tube used to demonstrate the principles of electrical glow discharge.

plural of geist

Ghost, apparition. / Spirit (of a group, age, era, etc).

(zoology) Any extinct cephalopod in the family Geisonoceratidae.

plural of geisonoceratid