grandam

[gran-duh m, -dam] /ˈgræn dəm, -dæm/
noun
1.
a grandmother.
2.
an old woman.
Also, grandame
[gran-deym, -duh m] /ˈgræn deɪm, -dəm/ (Show IPA).
Origin
1175-1225; Middle English gra(u)ndame < Old French grant dame. See grand, dame
British Dictionary definitions for grandame

grandam

/ˈɡrændəm; -dæm/
noun
1.
an archaic word for grandmother
Word Origin
C13: from Anglo-French grandame, from Old French grand- + dame lady, mother
Word Origin and History for grandame
n.

c.1200, "a grandmother; an old woman," from grand (adj.) + dame. Cf. Anglo-French graund dame. Contracted form grannam attested from 1590s.