Muse on this: the word muse comes from the Anglo-French muser, meaning “to gape, to idle, to muse.” (Amuse has the same source.) The image evoked is one of a thinker so absorbed in thought as to be unconsciously open-mouthed. Those who muse on their pets’ musings might like to know that muser is ultimately from Latin musus, meaning “mouth of an animal”—also source of the word muzzle. The sister goddesses of Greek mythology known as the Muses have no etymological link: that word, which in lowercase refers to a source of inspiration, comes from Greek Mousa. The ultimate Greek origin of the word museum translates as “of the Muses.”