Know why cattywampus was trending last week?
Old Testament people of coastal Palestine who made war on the Israelites, early 14c., from Old French Philistin, from Late Latin Philistinus, from Late Greek Philistinoi (plural), from Hebrew P'lishtim, "people of P'lesheth" ("Philistia"); cf. Akkad. Palastu, Egyptian Palusata; the word probably is the people's name for itself.
"person deficient in liberal culture," 1827, originally in Carlyle, popularized by him and Matthew Arnold, from German Philister "enemy of God's word," literally "Philistine," inhabitants of a Biblical land, neighbors (and enemies) of Israel (see Philistine). Popularized in German student slang (supposedly first in Jena, late 17c.) as a contemptuous term for "townies," and hence, by extension, "any uncultured person." Philistine had been used in a humorous figurative sense of "the enemy" in English from c.1600.