context Clues.
When you come to a word you do not know in your reading, you do not need to look up its meaning in a dictionary.
The best strategy for dealing with an unknown word is to try to guess what it means.
You can guess the meaning of many words from the context.
The context is the words around a new vocabulary item.
Sometimes a sentence gives the meaning of a new word and sometimes the meaning of the new one is in another sentence or in a longer passage.