[1860–65; ‹ Gk pý̄th(ein) to rot + -o- + -genic]This word is first recorded in the period 1860–65. Other words that entered Englishat around the same time include: Paleolithic, calibrate, metric system, mutualism, prep-o- is the typical ending of the first element of compounds of Greek origin (as -i- is, in compounds of Latin origin), used regularly in forming new compounds with elementsof Greek origin and often used in English as a connective irrespective of etymology(Franco-Italian; geography; seriocomic; speedometer); -genic is a combining form often corresponding to nouns ending in -gen or -geny, with the following senses: “producing or causing” (hallucinogenic); “produced or caused by” (cosmogenic); “pertaining to a gene or genes” (polygenic); “pertaining to suitability for reproduction by a medium” (telegenic)