murdermurder

The story

From Middle English murder, murdre, mourdre, alteration of earlier murthre (‘murder’) (see murther), from Old English morþor (‘secret slaying, unlawful killing’) and Old English myrþra (‘murder, homicide’), both from Proto-West Germanic *morþr, from Proto-Germanic *murþrą (‘death, killing, murder’), from Proto-Indo-European *mr̥tro- (‘killing’), from Proto-Indo-European *mer-, *mor-, *mr̥- (‘to die’). The -d- in the Middle English form may have been influenced in part by Anglo-Norman murdre, from Old French murdre, from Medieval Latin murdrum (whence the English doublet of murdrum), from Frankish *morþr, *murþr (‘murder’), from the same Germanic root, though this may also have been wholly the result of internal development (compare burden, from burthen and spider, from spiþra).