If you never watch one piece, I need to tell you this first:
Gear Fourth in One piece anime is a technic where luffy's body get bigger like a balloon (luffy is a gum man) and during that form he is not able to stand correctly and always bouncing (I believe he can't stop the bounce).
I already checked using google translated
バウンド could be translated as
Luffy's first Gear Fourth form is called Boundman (弾む男 (バウンドマン) Baundoman?, Viz: Bounce Man): Luffy's proportions become warped and his body becomes much larger in size, with his arms, upper torso, and legs coated in Busoshoku Haki.
so which one the better translation for this? or the both does make sense?