The story
From triosephosphate + isomerase, equivalent to triose + phosphate + isomer + -ase.
Etymology from Wiktionary, CC BY-SA 4.0.
triosephosphateisomerase
Today it means: An enzyme that catalyzes the reversible interconversion of the triosephosphate isomers dihydroxyacetone phosphate and D-glyceraldehyde 3-phosphate. Full definition →