cefalonium

Etymology tree
Translingual Cephalosporium
Proto-Indo-European *-nós
Proto-Indo-European *-iHnos
Proto-Italic *-īnos
Latin -īnusder.
Old French -inbor.
Middle English -in
English -ineclip.
English -in
English cephalosporin
Proto-Indo-European *-ikos
Proto-Italic *-ikos
Latin -icuslbor.
Old French -iquebor.
Middle English -ik
English -ic
English cephalosporanic
New Latin ammōniumbor.
English ammonium
English onium
English -onium
English cefalonium
From cephalo(sporanic acid) + -onium (“quaternary ammonium compound”).