Barrier crosswords are great for revising any vocabulary that you have taught in class. Below is an example of a barrier crossword I created for an English lesson when my EAL learners had been learning persuasive language techniques. As you will see from the images: one student has the clues down and one has the clues across. The idea is that learners describe or explain the word to their partner for them to guess. It practices skills such as clarifying, explaining, describing, and paraphrasing.
You can download the Word doc at the link below.