This is the 12715th most frequent Portuguese word.
turvas
"Turvas" means "murky" or "cloudy."
Here, 'turvas' is used as an adjective describing the condition of the river's waters, meaning they are not clear or clean.
As águas do rio estavam turvas após a chuva.
The river's waters were murky after the rain.
In this sentence, 'turvas' metaphorically represents the lack of clarity or vagueness in the person's memories.
Ela tinha memórias turvas daquele episódio da infância.
She had unclear memories of that childhood episode.
Here, 'turva' (feminine singular form of 'turvas') is used to describe the person's vision as unclear or indistinct.