Being multilingual meaning knowing more than one language is a quite useful skill to have in today’s world. Being multilingual is not just limited to speaking international languages like Spanish or Chinese with English, it can just mean knowing more than one language, be it any language. The term multilingual used to be used to refer to a person who knew two languages, but since the term bilingual began being used in the mainstream, the term multilingual meaning changed to refer to people who knew more than 2 languages. In the general sense of the word, however, it can be used to refer to people who know more than a single language.
However, this is not being used to refer to people who know more than one language because that would basically encompass almost every educated person on the planet. Being multilingual is a very good quality for teachers to have because it helps them convey concepts to their students in a better more understandable way. Some students might not be strong in English (assuming that is the medium of instruction) so having someone explain it to them in their mother tongue or in a language that is more familiar to them would help the students immensely.
There are a lot of advantages to being multilingual. Click here to read more about it.