While you read, you will bump into words you have never seen before. You do not always have to grab a dictionary. You can often figure out the word by using the other words and sentences around it. Those helpful hints are called context clues.
Context just means the words and sentences that surround the tricky word. Writers often drop clues nearby on purpose, like leaving footprints that lead you straight to the meaning.
One kind of clue is a definition right there in the sentence. If you read that the nocturnal owl sleeps all day and hunts at night, the sentence itself tells you nocturnal means active at night. The meaning was hiding in plain sight.
Another kind of clue is an example or a synonym, which is a word that means almost the same thing. If a sentence says a boy was famished, so hungry his stomach growled, the words after the comma show you that famished means very hungry.
Here is your plan: when you meet a hard word, read the whole sentence, and even the sentence before and after. Ask yourself what would make sense there, then guess the meaning and check if it fits.
Context clues make you a stronger, faster reader because you do not have to stop every single time. You become a word detective who solves the mystery using the clues the writer left behind.