Etymology: < classical Latin rōs marīnus or rōsmarīnum sea dew, rosemary < rōs dew (see rore n.) + marīnus or marīnum , masculine and neuter respectively of marīnus marine adj. Compare Old French rosmarin (13th cent.), Middle French rommarin (c1393), rousmarin (c1400), roumarin (15th cent.), Middle French, French romarin (2nd half of the 14th cent.), Old Occitan romanin , Catalan romani (a1376), Portuguese rosmaninho (a1580), Italian rosmarino (14th cent.); Spanish romero (c1325) is probably < classical Latin rōs maris in this sense: see below. Compare also in the Germanic languages Middle Dutch rosemarine , rosemarijn (Dutch rosmarijn , rozemarijn ), Middle Low German rōsmarīn , rōsemarīn , rōsemarīne (late 15th cent), rōsemarīne (1617), early modern German rosenmarin , roszmarin (15th cent.; German Rosmarin ), Swedish rosmarin (1572), †rosenmarin (1602), Danish rosmarin (16th cent. as † rosenmarinn ). Compare rosemary n.The Latin name also appears as marīnus rōs and rōs maris (and also simply as rōs ), and has been supposed to have reference to the plant's growing near the sea. Folk-etymological reanalysis of the first element as showing rose n.¹ and its cognates appears to have been widespread, perhaps suggested by the post-classical Latin variant rosmarina , feminine (first half of 11th cent. in a British source). This reanalysis is shown particularly clearly by early modern German rosenmarin ; compare also English forms in rose- , and forms at rosemary n., and also Anglo-Norman rosemaryn , Anglo-Norman and Middle French rosemarin (14th cent. or earlier), and post-classical Latin rosa marina (15th cent., 1570 in British sources (glossaries)). In the early Middle English form rosmarini at α. forms apparently after the Latin genitive singular. It is uncertain whether the following early example of the β. forms shows the Middle English or the Anglo-Norman word:c1300 in T. Hunt Plant Names Medieval Eng. (1989) 222 [Ros Marinus] rosmaryne.

Etymology: Probably < post-classical Latin rosmarus (1558 in Gesner; probably < Old Danish rosmar (also rosmer , rossmer , rosmaal ; compare Old Icelandic rosmhvalr , rosmall , Norwegian regional rossmal , rosmaal , rosmaar ) < a first element of uncertain identity + the Scandinavian base of Old Icelandic hvalr whale n.; see further discussion at walrus n.), with alteration of the ending, perhaps after marine adj. (compare e.g. mors marine in this sense in quot. 1482 at morse n.² 1). Compare Italian rosmaro (1583 or earlier), Spanish rosmaro manatee (1628), < Latin.