Strengthen Vocabulary, Context Clues, Using a Dictionary/Glossary

How do you use a dictionary/glossary?

A dictionary is a large book or electronic resource that contains the definitions of virtually all English words.You can use a dictionary to look up the meaning of any words that you don't understand.

Words in dictionaries are organized by alphabetical order to make it easy to search for a word. The image shows what a dictionary entry may look like:

The word being defined is typically bolded. You will probably find this word closer to the beginning of a dictionary, since it starts with a B.The dictionary will then list several different definitions, since a lot of words have multiple meanings. Before a definition, the dictionary will typically state what type of word it is (noun, adjective, adverb, etc.). Dictionaries may also include an example sentence that uses the word to let you know how it can be used while talking or writing.

A glossary is very similar to a dictionary, but is typically a list of definitions relating to a specific subject, usually found at the end of some type of writing (like an article, or textbook). It is much shorter than a dictionary.

What are word roots (affixes)?

Word roots, or affixes, are word segments that modify the meaning of an entire word. An affix at the beginning of a word is called a prefix, and an affix added to the end of a word is a suffix.

An example of an affix is the “uni-” in the word unicycle. Since it is at the beginning of the word, it is a prefix. “Uni-” means “one,” so words that have it as an affix have a meaning that relates to “one” (for example, unite, universe, unison).

Here are some word roots you should memorize:

1. graph: write

2. scope: see

3. terr: land

4. photo: light

5. dict: to say/tell

6. sci: to know

7. temp: time

8. aero: air

9. nov: new

10. cent: hundred

Can you think of any words with these affixes? One example for root #6 (sci) would be science.

After reviewing the word roots above, try to complete the following activity on the right without looking at the meaning of the roots.

What are synonyms, antonyms, and homophones?

1) Synonyms are different words that have similar meanings. For example: sad, upset, unhappy, and glum all mean similar things.

2) Antonyms are words that have opposite meanings. You could say that “antonym” is the antonym for “synonym!” The antonym for “sad” would be something like “happy.”

In the activity below, try to match the words on the left with their antonyms on the right:

3) Homophones are words that sound the same, but have different meanings. Homophones can be spelt the same way, or differently. “Hi” and “high” are homophones because they sound the same, but mean different things.

What is a synonym for “happy?”

What is an antonym for “pretty?”

What is a homophone for “two?”

Review all the terms you just learned with the matching quiz below!


You should try to learn the definitions of all the words below. For the words you don’t know, try using a dictionary to look up their definitions! Pick a couple of the words and see if you can find synonyms, antonyms, or homophones of the word (though most of them probably don’t have homophones). Can you also identify some word roots in a couple of the words below?

What are context clues?

Context clues are hints found within a sentence, paragraph, or passage that a reader can use to understand the meanings of new or unfamiliar words. Even if you don’t know the exact definition of a word, you can guess the general meaning of it by how it is used inside a piece of writing. Take a look at the sentence below:

The storm made the ocean waters turbulent, so the pirate ship was tossed around violently in the sea.

Even if you don’t know what turbulent means, you can tell that it’s an adjective describing the stormy waters, which tossed around a pirate ship. From there, you can guess that turbulent describes something that moves unsteadily or violently, causing disorder and confusion.

Read the following passage and answer the questions using context clues:

Spiders, insects, centipedes, mites, ticks, lobsters, crabs, shrimp, crayfish, krill, barnacles, and scorpions are all arthropods. 85% of all known animals in the world are arthropods. All arthropods share four characteristics. First, they all have a segmented body. Spiders have two segments. Flies have three segments. Centipedes can have anywhere from 15 to 177 segments! Second, they have many jointed limbs. Spiders have 8 limbs. Millipedes can have hundreds. Third, all arthropods have an exoskeleton which protects their internal organs. This exoskeleton is soft when arthropods are born, but soon hardens into an armor‐like covering. This covering, which is shed and replaced periodically as the arthropod grows, is necessary because as invertebrates, arthropods do not have a backbone. Finally, all arthropods are cold‐blooded, meaning that they cannot regulate their own body temperature. The temperature of their body depends on the temperature of their environment.

DIRECTIONS: Choose the best meaning for each bold‐faced word from the passage.

Then write the clues from the passage that helped you choose the correct meaning.

1. Characteristics means: A. feature B. part


2. Segment means: A. part B. hard


3. Limbs means: A. branch B. arm or leg


4. Exoskeleton means: A. exterior skeleton B. without a skeleton


5. Periodically means: A. from time to time B. always


6. Invertebrates means: A. no backbone B. no skeleton


7. Regulate means: A. supervise B. control