Trimethylamine :: Trimethylamine (n.) A colorless volatile alkaline liquid, N.(CH3)3, obtained from herring brine, beet roots, etc., with a characteristic herringlike odor. It is regarded as a substituted ammonia containing three methyl groups..
Trimethylene :: Trimethylene (n.) A gaseous hydrocarbon, C3H6, isomeric with propylene and obtained from it indirectly. It is the base of a series of compounds analogous to the aromatic hydrocarbons..