Masking

I’ve heard the term “masking” in relation to autism - I don’t know what this means - does it mean pretending that you don’t have Autism? Someone told me it’s pretending to be intelligent by using “big words” when someone knows too much about certain things (that it is deemed they should not know anything about) and not enough about those things that everyone else “should” know about and where such people need to get “put in thier place”