A mongrel is a dog that you cannot tell what breed it is. Mongrels might simply be cross breeds, but are usually stray dogs that have been mixed breed for so long there is no way of telling what their ancestry is.
A pedal is a device that you operate with your foot. Pedals are found on all sorts of devices, like pianos, electronic keyboards and an assortment of other musical instruments, sewing machines, and of course bicycles.
