You know when your reading a book and at the bottom of the page is a list of words alongside with the definitions of those words, what is it called?(its a text feature)
It’s what you call a mini dictionary for you when words are used from the 90’s or the olden times rather than what we use now and days so people insert them so you can understand what the words mean and you know the meaning or saying in the text. Hopes this works :)
