The word crap is actually of Middle English origin and predates its application to bodily waste. Its most likely etymological origin is a combination of two older words: the Dutch krappen (to pluck off, cut off, or separate) and the Old French crappe (siftings, waste or rejected matter, from the medieval Latin crappa). In English, it was used to refer to chaff and also to weeds or other rubbish. Its first recorded application to bodily waste, according to the Oxford English Dictionary, appeared in 1846, 10 years after Crapper was born, under a reference to a crapping ken, or a privy, where ken means a house.
This man was fated to give a crap
