Wiktionary
n. The particulate matter suspended in bodies of water such as lakes and seas. It applies to all particulates, including plankton, organic detritus, and inorganic material.
Wikipedia
Usage examples of "seston".
She had flirted with Calbert Seston one day out behind the schoolhouse, but he had not seemed to be aware that she was flirting and he never paid any more attention to her than he had before.
G albert Seston did not seem to have any greater awareness of her existence.
Miss Elmore was nowhere to be found, but Cal Seston was making his presence felt.
And he put his hand on her shoulder, turned her toward the door, and walked between her and the sight of Cal Seston until they were out of the room.
Then she realized that Calbert Seston was holding the reins of the wagon and Megan Henshaw was coming toward the gate to see her.
It was getting dark and a little chilly and she did not particularly want to see Cal Seston again.