I like to try and translate in-game signs and books for fun, as most of them have a clear meaning and use English words. However, I have no idea what “yundumi” or “yungumi” are supposed to mean. At first I thought it might have been Yunobo’s name prior to localization, but his original name is ユンボ (Yun-bo) so that can’t be it.

In case you’re curious where the translated letters come from, click here

EDIT: It is very likely the original name of “Yunobo Co.” as the suffix “-gumi” refers to an organisation or group in Japan.