The word is only found in a fifteenth-century medical manuscript (Plant Names C18) and in a fourteenth-century Middle English herbal (Plant Names B2). Despite its designation in the gloss as both English and French it is not found in any of the medieval dictionaries. The Latin word glossed (camepitheos) is probably the plant chamaepitys (DMLBS 323a, from Greek χαμαιπιτυς, defined as ‘ground-pine or germander’ or ‘hemp or other plant’). The other vernacular gloss, mederatele, is found in the MED as a compound sub mede n.2 (i.e. ‘meadow), where it is defined as ‘a kind of plant similar to the Germanders’. The AND’s definition relies upon the senses of the Latin and English terms, and the precise meaning and etymology of the gloss osatille remains unclear.