Piggyback

Piggyback is a corruption of the earlier expression ‘pick-a-back’, which means to carry someone or something on one’s back. Therefore, it really has nothing to do with pigs, the animals. The precise origin of pick-a-back (especially the ‘pick’ part) remains unknown, but one theory is that it derives from the simple act of picking something up and carrying it. Pick-a-back dates from the mid-16th century and became corrupted to piggyback by the late 19th/early 20th century.