Answer:
"Nearly" is a adverb.
Explanation:
The word "nearly" is an adverb that expresses intensity, quantity. This word means "almost", "approximately", "near".
Adverbs are a class of words that act directly on the verb. These words are so characteristic of the verb, but they can also give characteristics to other grammatical classes, as is the case of the sentence shown in the question above. In this sentence, the adverb "nearly" characterizes the noun "athletes", characterizing it in relation to quantity.