(geometry, engineering) Tetrahedral.

(informal, numismatics) Clipping of tetradrachm.

(informal, fishkeeping) A tetra (freshwater fish).

(informal, medicine) Clipping of tetanus.

Vietnamese New Year celebration, occurring during the first seven days of the first month of the lunar calendar.

An ancient Egyptian symbol of the god Osiris, in form a small pillar with a number of flat sections towards the top.

(chemistry) Initialism of tetraethyltin. / (computing) Initialism of transparency-enhancing tool. / (medicine) Initialism of thymic epithelial tumor. / (physics) Initialism of targeted energy transfer.

(informal, organic chemistry) Clipping of carbon tetrachloride.

(medicine) An acute episode of hypoxia in an individual with tetralogy of Fallot.

(voodoo) The loa with whom a Vodouisant has a particular connection, and with whom they specially identify.