A "vocabulary builder" is something that helps expand and improve your knowledge of words and their meanings. It provides a way to learn new words and strengthen your language skills. Full definition
Many owners do not realize that games are also good vocabulary builders. (siriusdog.com)
«[A] winning vocabulary builder for young readers... The many unrelated contrasts in this companion volume afford even greater opportunity for whimsy and variety in the illustrations.... (peachtree-online.com)
Game instruction guide Playing board 24 starter Macbeth words Powerful Spelling and Vocabulary builder ✔ ✔ A blank Macbeth spelling template file that allows you to input, print and use your own words Two Macbeth double puzzle quizzes - anagrams and a hidden message Two Macbeth word search quizzes (tes.com)