cetrimonium

Etymology tree
Ancient Greek κῆτος (kêtos)bor.
Latin cētus
Proto-Indo-European *swel-der.?
Ancient Greek ῡ̔́λη (hū́lē)der.
Frenchder.
English -yl
English cet(yl)
Proto-Indo-European *tréyes
Proto-Indo-European *tri-
Proto-Italic *tri-
Latin tri-der.
English tri-
Proto-Indo-European *médʰu
Proto-Hellenic *métʰu
Ancient Greek μέθυ (méthu)
▲
Ancient Greek ῡ̔́λη (hū́lē)der.
German -yl
German Methylbor.
English methyl
English trim(ethyl)
New Latin ammōniumbor.
English ammonium
English onium
English -onium
English cetrimonium
From cet(yl) + trim(ethyl) + -onium (“quaternary ammonium compound”).