A noun for “sheep” in the Gnomish Lexicon of the 1910s given as {mô >>} moth (GL/58), likely derived from the early root ᴱ√MAWA “cry, bleat” that was the basis for “sheep” words in Early Qenya (QL/060).
Gnomish
mam
noun. grandmother, mother
baba
noun. mummy, mamma
babi
noun. mummy, mamma
(m)ami
noun. mummy
amaith
noun. mother
ami
noun. mummy
amil
noun. mother
mab(a)
noun. mother
mabir
noun. mother
mad-
verb. to eat
moth
noun. sheep
nanwin
noun. mother
nân
noun. mother
A noun appearing as mam “grandmother, mother” in the Gnomish Lexicon, derived from ᴱ√maƀ or mam “something nice” (GL/57).
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.