murder [OE] The ancient root of murder is shared by Latin mors ‘death’, from which mortal [LME] also derives, as do words at *mortuary. In his Canterbury Tales Geoffrey Chaucer wrote ‘Murder will out’. The idea is older, but his concise way of expressing it ensured that it became proverbial. From the 18th century *blue was thought of as the colour of plagues and of harmful things in general, and someone being attacked would cry or scream blue murder to emphasize their plight. The phrase now refers to making a noisy protest.