From the Greek, galakto (milk) + phor (from amphora meaning a container for transporting valuables) + ous (full of)

The same rationale as above is used in the meaning of Lactiferous ducts the ducts that converge and form a branch system that connect the nipple to the lobules of the mammary gland.  They are also referred to as milk ducts, mammary ducts, and galactophorous ducts.