The hikers guessed that it would take 3 full days to reach the pinnacle or top of the mountain. what context clue was used?

I have found this question online. it concerns context clues and the word "pinnacle"

In the sentence provided, to guess the meaning of "pinnacle", we used a synonym.

Explanation:

Context clues are used to help us guess the meaning of new words in a text. There are different kinds of context clues, the most common being synonyms, antonyms, or direct definitions.

A synonym is a word that has the same meaning as another word. When authors suppose their readers might not know the meaning of a certain word, they may provide a synonym to help them understand the new word. That is precisely what happens in "The hikers guessed that it would take 3 full days to reach the pinnacle or top of the mountain." The word "pinnacle" is not so commonly used, so readers might not know what it means. The author then places a synonym right after it, "top", to make sure readers understand it.