Many slang or informal words meaning ‘big’ are related to hitting or striking eg thumping, whacking, strapping, and whopping. Bouncing, too, is often used with the sense ‘big’ (a bouncing baby is a healthy, vigorous one), since the original sense of the verb ‘bounce’ (in the 13th century) was to beat or thump. In the 16th century its meaning widened to include noise or sound – the OED definitions include “to make a loud explosive noise; to talk loudly or bigly” and “to slam or bang (a door)”. At around the same time the phrase “to bounce it” was used of women dancing and bounce also acquired its current meaning (as the OED has it, “to bound like a ball”). To bound meaning 'jump' only appears in English in the late 16th century. It has a French origin (bondir), whereas to bounce seems to be linked with Dutch (bonzen, to thump) and Low German (bunsen, ditto).