I don't think there is one name in US English either. In Caribbean restaurants in the US they call it chocho. The first time I saw it, I confused it with the term in Spanish which is a sugary hard cookie. This one is neither sugary nor hard. Mirleton is used as an ingredient in southern cuisine and it appears to be the same fruit/vegetable. I also wouldn't be surprised if they called it Chayote too in some places. The problem with so many terms is that this fruit/vegetable hasn't caught on except locally in some communities and so most people don't know what it is.
I've never seen it in its raw form, come to think of it, as it's mostly used to make soup (together with carrots and sweet corn) in Cantonese cuisine. It's known as hap6zoeng2gwaa1 合掌瓜 "joining-palms-squash", with "joining palms" referring to the "namaste gesture".