We don't have synonyms for reiver yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are river, reaver and reiner.
(n) :
a large stream of water that alters the nearby landscape. Occasionally rivers overflow their banks and cause floods; any large flow of a liquid in a single body (e.g., 'a river of blood')
(v) :
to improve one's hand to beat another player on the final card in a poker game
(n) :
a large stream of water that alters the nearby landscape. Occasionally rivers overflow their banks and cause floods; any large flow of a liquid in a single body (e.g., 'a river of blood')
(v) :
to improve one's hand to beat another player on the final card in a poker game