7. Referent Clues A referent clue is when an unknown word is referred to (mentioned) again using a synonym or explanation of the word. Synonyms often follow words like this, that, these, those, or the. Sometimes, however, there is no obvious clue word. The reader just sees that the meanings are probably similar from the ideas in the sentence. Look at this example: She yelled out the window at her neighbor's dog. Then she said to her husband, "That hound is always waking me up at night with its barking, Tomorrow I'm going to complain." In this example, that comes before the unknown word. This suggests that a hound has already been mentioned. We can guess that that hound refers to the dog. So, a hound is probably a dog.