Noun (1)
from (assumed) Medieval Latin datarius datary, official of the Roman Curia who added dates to papal letters (whence New Latin), from Late Latin data date of a letter + Latin -arius -ary (person)
Noun (2)
from (assumed) Medieval Latin dataria datary, office of the Roman Curia where dates were added to papal letters (whence New Latin), from Late Latin data date of a letter + Latin -aria -ary (thing)