trimethylamine

noun

tri·​meth·​yl·​amine ˌtrī-ˌmeth-ᵊl-ˈam-ˌēn, -ə-ˈmēn 

: an irritating gaseous or volatile liquid tertiary amine (CH₃)₃N that has a fishy odor, is only slightly more basic than ammonia, is flammable and forms explosive mixtures with air, is formed as a degradation product of many nitrogenous animal and plant substances, and is used chiefly in making quaternary ammonium compounds (as choline)