ᴺS. [G.] mam n. “grandmother, ⚠️mother” (Category: Grandmother)
Neo-Sindarin: As we have no other attested alternatives, I would use ᴺS. mam for “grandmother” in Neo-Sindarin, based on a Neo-Root ᴺ√MAB (from primitive *mamba), but would not use it as “mother” for which we have plenty of later words.
Reference ✧ GL/57 ✧ “grandmother, mother”