Translation:A cotton wrap
That's it! It can also be worn around the waist. Some people have one around the waist and a matching one on top. They can also be worn around your waist over your other clothes, like an apron for the bottom part of your body. They can also be used for tying a baby onto your back. So useful!
What else would you translate it with? I think they just want you to know that it is a common piece of clothing in Swahili speaking countries, even if there is no good English translation. I think that's good, and there's ought to be a few words like that when country contexts are different.