Which English words (that are not proper nouns) stem from the names of rivers? Let's set aside, as not very interesting, the terms for people or cultures from an area close to or related to the river (which might be proper nouns in any event).

Please check your answers (for instance, in dictionary.com) before posting them, rather than just relying on vague memory or guesswork. Note that I might (or might not) delete some comments that seem to be nonresponsive or duplicative in order to keep the thread focused on the answers.