Middle high german has 3 different meanings across 2 categories:
High German from 1100 to 1500
Concerning the Middle High German language.
An ancestor to the modern (High) German language, spoken from 1050 to about 1500. Some linguists prefer to use 1350 as the end of the Middle High German period, calling the period from 1350 to 1650 Early New High German in a broad sense.