(philosophy) The Fichtean ego that posits its own existence and through the opposition of subject and object thus created dialectically evolves the universe.

A species of passerine bird, Lonchura flaviprymna, of northern Australia.

(organic chemistry) The polyketide (5S,6R)-1-[(2E,4E,6S)-4,6-dimethylocta-2,4-dienoyl]-5,6-dihydroxy-5-methyl-6,7-dihydro-2-benzofuran-4-one present in the Aspergillus fungus

(inorganic chemistry) The binary compound of silicon and fluorine SiF₄, a colourless, poisonous gas with a pungent odour, used in the production of silicon semiconductors.