This is the 3402nd most frequent Japanese word.
沢
"沢" (sawa) means "marsh," "swamp," or "stream" in English.
沢 is used here to refer to a 'stream' or 'valley' in a natural context.
この森には美しい沢が流れています。
A beautiful stream flows in this forest.
沢 is part of the word '沢山', meaning 'a lot' or 'many', used to denote a large quantity.
彼は沢山のお金を持っています。
He has a lot of money.
沢 is directly used to mean 'valley' or 'stream', referring to a geographical feature.