This is the 14th most frequent Portuguese word.
das
"Das" is the contraction of "de" + "as," meaning "of the" or "from the" for feminine plural nouns.
Here, 'das' is a contraction of the preposition 'de' (of) and the feminine plural definite article 'as' (the), used to indicate belonging to a group referred to by 'melhores jogadoras' (best players).
Ela é uma das melhores jogadoras do time.
She is one of the best players on the team.
In this instance, 'das' appears as a contraction of 'de' and 'as', used to indicate the possession of 'som' (sound) by 'ondas' (waves).
O som das ondas é relaxante.
The sound of the waves is relaxing.
Here, 'das' is a contraction used with 'de' and the article 'as', indicating the subset or selection from a group mentioned.