Simplify the following text for a Grade 7 native English-speaking person.
Original: The word Sepasco probably originated from the tribe 's word for little river or stream , sepuus , which is believed to have referred to the Landsman Kill , a stream parallel to NY 308 .
Simplified: The word Sepasco probably came from the tribe 's word for `` little river '' or `` stream '' , which is sepuus .