Lesson: Using a Thesaurus to Define an Unknown Word
Connection (3-5 mins): Yesterday, we learned how to look up a word in the dictionary. This is a great way to understand the definition of a word. There is another way to find the meaning of a word by using a thesaurus. This is another type of reference that we will work with today to learn the meaning of unknown words.
Teach (10-12 mins): Students should be seated on the carpet with a partner. They will be expected to turn and talk to this partner throughout the lesson. A thesaurus is a tool that we can use to find synonyms for unknown words. We talked about in a previous lesson that we can use synonyms or words that mean the same thing to understand the meaning of a word. A thesaurus is a book that gives us synonyms for words. As a reader if we know the definition for one of the synonyms we then know the definition of the unknown word.
Teacher places a thesaurus page on the overhead. What do you notice about this page? Turn and tell your partner. Students turn and talk while teacher listens in to their conversations. Teacher calls on students to share out their responses. You all noticed a lot about this page. It is important to pay close attention because before the end of the lesson you will be asked to use a thesaurus on your own.
Let’s look at the article, “When Ants Go Marching” again to see if there are more words we do not understand. Teacher reads aloud the paragraph under the heading, Old Ideas. I do not know the meaning of the word navigate and this makes that sentence really confusing. An option I have is to look in the thesaurus and see if I know the definition for any of the synonyms for the word navigate. Teacher looks in the thesaurus and shows students on the overhead. My thesaurus gives three options for synonyms. It lists journey, plan, and travel.
Using what I know about the sentence, I can guess that when ants navigate in the dark it means they travel at night. The thesaurus is really helpful because I learned many different synonyms for the word navigate. Now I have understand the meaning of the sentence and I have a word to substitute as I continue reading.
Did you see another word in this paragraph you did not know? Turn and tell your partner that word. Students turn and talk. Teacher has students share and charts a list of words that will be looked up later in the lesson.
Now we have a great list of words we do not know. I purposefully picked an article to read that has a lot of difficult vocabulary so we would have more time to practice. Let’s begin looking up each of these words. Teacher gives each partnership a thesaurus (if the class if bigger or not as many words were listed, students can work in groups of three or four). Teacher assigns each group a word to look up in the thesaurus. Once you have found your assigned word, raise your hand and I will have you write a synonym on our classchart.
Teacher allows students time to search for words and calls on students who are ready to share to write on the chart. After each student has found their assigned word, teacher calls the group back to attention. Great job readers! Look at all the new words and synonyms we have learned today by using the dictionary. This is important because without understanding the meaning of these words we may not have learned anything from the article.
When you return to your seats, you will practice this same skill with your own independent reading book. A thesaurus should already be at your table to share with your group mates. Off you go readers.
Active Engagement (15-20 mins): Students return to their seats to work independently. Teacher should conference with students or pull small groups of students who may be struggling. Students should read in their independent reading books during this time to locate words they do not know. Each time they locate an unknown word, the word should be recorded in their thesaurus chart. Every student must have access to a thesaurus for this lesson to be successful or students may share at their tables. Students should record words that are synonyms for the unknown word in their chart as well that are found in the thesaurus. The goal is for students to then define the unknown word based on synonyms found in the thesaurus. Students will be asked to share at least one unknown word after workshop time.
Exit Slip/Share (3-5 mins): Each student should be given a chance to share out one word they learned during the lesson. Teacher can also collect thesaurus charts to monitor student mastery. This serves as a great formal assessment because students should be able to define the word based on information in the thesaurus. Those students who do not master the skill may be pulled for small group remediation during following lessons.
Reflection: This lesson is much easier to assess than previous lessons using a reference. It requires that students use their knowledge of words and synonyms to construct their own definitions of unknown words. This exposure to more words will only improve their reading levels and in turn increase their fluency/comprehension. It is difficult to provide each student with a thesaurus but I suggest borrowing some from your school library or having students share for this lesson.