the term is a modern scientific compound, systematically constructed from international scientific vocabulary. the prefix "tri-" directly indicates the presence of three chlorine atoms. the element "chloro-" derives from the greek word for the pale green color characteristic of chlorine gas. the base "ethylene" refers to the two-carbon hydrocarbon skeleton (ethene) to which the chlorine atoms are attached. thus, the name transparently describes the molecule's chemical composition: an ethylene molecule where three hydrogen atoms have been replaced by three chlorine atoms.

Structure: tri (three) + chloro (chlorine) + ethylene (ethylene) tri: from greek and latin, a numerical prefix meaning "three". chloro: from greek 'khlōros' (greenish-yellow), a combining form meaning "chlorine". ethylene: from 'ethyl' (the name of a hydrocarbon radical) + the chemical suffix '-ene' (denoting an unsaturated hydrocarbon containing a double bond).