A word for “grandfather” of unclear derivation appearing as ᴱQ. haru in both the Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s (QL/39; PME/39). As there are no other alternatives, I would retain ᴺQ. haru for purposes of Neo-Quenya.
Early Quenya
síre
noun. stream
(m)ambe
noun. mother
ama
noun. mother
amaimi
noun. mother
ambe
noun. mother
ambi
noun. mother
amis
noun. mother
ammi
noun. mother
atar
noun. father
atta
noun. father (child’s word)
attahwi Archaic
noun. parents
atto
noun. father
attu
noun. father
haru
noun. grandfather
haruni
noun. grandmother
The word ᴱQ. haruni “grandmother” appeared in both the Qenya Lexicon and Poetic and Mythological Words of Eldarissa of the 1910s (QL/39; PME/39). It is a combination of ᴱQ. haru “grandfather” with the female suffix -ni. As there are no other alternatives, I would retain ᴺQ. haruni “grandmother” for purposes of Neo-Quenya.
puyando
noun. parent
A neutral word for “parent” in English-Qenya Dictionary of the 1920s (PE15/76). Its dual form puyandui referred to both “father and mother” (PE15/72). The dual form also appeared in the Early Qenya Grammar, where Tolkien connected it to the verb ᴱQ. puita- “beget” (PE14/77).
sindi
noun. river
A noun in the Qenya Lexicon of the 1910s glossed “river” derived from the root ᴱ√SIŘI [SIÐI] (QL/84). The same word appeared in the contemporaneous Poetic and Mythological Words of Eldarissa (PME/84).
siri-
verb. flow
tatto
noun. father
âmi
noun. mother
An archaic dvanda dual form in the Early Qenya Grammar of the 1920s referring to both parents based on older atta(h)-, replaced by the dual atarqi of ᴱQ. atar in normal speech (PE14/77). As a dvanda dual, it was based on the word for “father”, with “mother” being implied. It also appeared in an (archaic?) plural form attahi in the English-Qenya Dictionary, but presumably this only meant “fathers” (PE15/72).