Answer:
Use context clues.
Step-by-step explanation:
Anytime you encounter an unknown word, you can try to use contextual clues to figure out more about it. For example, if you have "David sat with the new book for hours. He was so engrossed in the truck section that he did not realize his mother was asking him to take out the trash." By looking at this sentence we can see that David's mother is telling him something, but he is unaware of that. From the sounds of the sentence, we know he is interested in his new book. These clues are telling us "engrossed" could mean something like "deeply interested" especially since he was so interested he was unaware his mother was talking to him.
Another example would be "The majority of the fourth-grade class was appalled by the dissection of the frog, but Anglica was engrossed. She couldn't stop staring at it in wonder and with a smile on her face kept prodding the contents of the stomach." From these contextual clues we know that she is "fascinated" and "filled with wonder" and that clearly the frog is holding her interest.
The other answers do not make sense because practiciing pronouncing a word is unhelpful unless you are examining root words. Spelling the unknown word is equally unhelpful because it is not showing you what the word means. Memorizing a phrase will not help you figure out what a word is.