RhymeZone: trimethylbenzene definitions

Definitions of trimethylbenzene:

noun: (chemistry) Any of three isomeric chemical compounds: 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene (pseudocumene), and 1,3,5-trimethylbenzene (mesitylene).

(Definitions from Wiktionary)