This lovely, quintessentially British appellation, also spelled Rosamond, is the name of a legendary twelfth-century beauty. Rare on these shores, it is more than worthy of importation.
There was a time when Rosamund wasn't quite so unusual in the US--she ranked on the Top 1000 from 1881 to 1930, reaching 574 in 1912.
Early on, the name was associated with 'fair Rosamond' Clifford, mistress of Henry II, whose story was the basis of the Joseph Addison opera Rosamund and the Swinburne play of the same name. Rosamund Vincy is a character in George Eliot's novel Middlemarch.
Another, literal, translation of the names meaning is 'rose of the world.'
A current bearer is actress and one-time Bond girl Rosamund Pike--who has a son named Solo.