You think Mittens the kitten is gentle and sweet, and then one day she runs amok, ripping up Grandma's favorite armchair until its cottony guts are hanging out. Time to take Mittens to get her claws trimmed.
Most of our words are rooted in Greek, Latin, or German, so it's refreshing to see a word that arose in a whole different language: amok's origins are in the Malay language of Indonesia. In the 1500s, a Portuguese writer and explorer named Duarte Barbosa described a murderous tribe on the island of Java as the "Amuco," and the word passed on into English. Amuco came from Amuk, a Malay word meaning "attacking furiously."