[1645–55; ‹ eccl. Gk euchológion prayer book, equiv. to euch(e᷄) prayer + -o- -o- + -log- word + -ion n. suffix]This word is first recorded in the period 1645–55. Other words that entered Englishat around the same time include: capsule, complex, herringbone, revival, simmer-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)