trimethylbenzene

== English == === Etymology === From trimethyl +‎ benzene. === Noun === trimethylbenzene (countable and uncountable, plural trimethylbenzenes) (chemistry) Any of three isomeric chemical compounds: 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene (pseudocumene), and 1,3,5-trimethylbenzene (mesitylene).