Origin: ME costmarye < cost (< OE < L costum < Gr kostos, name of an aromatic plant) + Marie, (St.) Mary
See costmary in American Heritage Dictionary 4
noun pl. cost·mar·ies
Origin: Middle English costmarie
Origin: : cost, costmary (from Old English, from Latin costum, from Greek kostos, from Sanskrit kuṣṭhaḥ)
Origin: + marie, Mary, the mother of Jesus.