"aged woman," 1570s; earlier "grandmother" (mid-15c.), from dame
(q.v.) in the sense of "mother" + bel-
, M.E. prefix expressing relationship (cf. belfader, belsire
"grandfather"), from O.Fr. bel, belle
"beautiful, fair, fine." This "direct relationship" sense of bel
is not found in French, where the prefix is used to form words for in-laws.