We don't have synonyms for raintree yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are rain tree, braintree and aintree.
(n) :
Alternative form of rain tree. [A tropical American tree (Albizia saman) having bipinnate leaves, globose clusters of flowers with crimson stamens, and sweet-pulp pods eaten by cattle, also used as an ornamental.]
(n) :
Alternative form of rain tree. [A tropical American tree (Albizia saman) having bipinnate leaves, globose clusters of flowers with crimson stamens, and sweet-pulp pods eaten by cattle, also used as an ornamental.]