What's the "een" in Halloween?
c.1300, from Pantheon, name of a temple for all the gods built in Rome c.25 B.C.E. by Agrippa (since 609 C.E. made into the Christian church of Santa Maria Rotonda), from Greek Pantheion (hieron) "(shrine) of all the gods," from pantheion, neuter of pantheios, from pan- "all" (see pan-) + theios "of or for the gods," from theos "god" (see Thea). Sense of any group of exalted persons is first found 1590s.