In some ways this is a variation of banned words or key words. Each student is given a secret word. They need to use this word as often as they can without anyone else guessing what word they have been given.
It can also be reversed - each student has a secret "banned" word, which they can't use for the lesson. The challenge can either be for them to simply get through the lesson, or they need to get other students to guess what the word is (kind of like charades, but talking is permitted)
I have also used this as a short, small group, card based game. I make up cards which have at the top a word which the student needs to get the others in the group to guess. To make it challenging, I add some other words which the student also may not use to the card. Example cards could be:
TEA (drink, hot, coffee)
UNIVERSITY (study/learn, student, school)
In Indonesian, I will often use a base-word (eg "ajar") which the students can not use. It means that they can use a different word that means the same thing if they can think of it, but also increases the range of banned words as they can not use any words that use that base.
At the end of the game, you can ask students to make their own suggestions for cards to use in the future. I have been using the same set of cards for a few years now, just adding to it from time to time. Once you've made up the cards, it's easy!