For the second meaning, cf. Hadorion, a Húrin's epithet in WJ/294, Hurinionath referring to the house of Húrin the Steward in PM/202-3,218, and Gil-Galad's epithet Ereinion, cf. also the gloss of the old Qenya cognate yondo "descendant of" in PE/12:106, or the use of the same suffix in later Quenya names such as Isildurioni and Anárioni "Heirs of Isildur (resp. Anárion)" in PM/192,196
Noldorin
hann
adjective. intelligent
hann
adjective. intelligent
hannas
noun. understanding, intelligence
hannas
noun. understanding, intelligence
hand
adjective. intelligent
-ion
suffix. son
anna-
verb. to give
gwador
noun. brother (especially used of those not brothers by blood, but sworn brothers or associates)
had-
verb. to hurl
hadh-
verb. sit
haf-
verb. to sit
heniad
gerund noun. understanding, intelligence
ionn
noun. son
ionn
noun. scion, male descendant
ionn
noun. son
muindor
noun. brother
muindor
noun. brother
tôr
noun. brother
The word muindor is more usual
tôr
noun. brother
An (archaic) word for “brother” in The Etymologies of the 1930s derived from the root ᴹ√TOR of the same meaning, with an irregular plural terein (Ety/TOR). In ordinary speech, it was replaced by muindor, with an initial element muin “dear”.
Neo-Sindarin: In notes from the late 1960s, Tolkien introduced a new word hanar for “brother” (VT47/14). However, I think †tôr and related words might be retained to mean a “metaphorical brother”, a close male associate who may or may not be related by blood, as with such words as gwador “(sworn) brother, associate”. In this paradigm, I would assume muindor still refers to a brother by blood, with an added connotation of strong affection.
For the second meaning, cf. Hadorion, a Húrin's epithet in WJ/294, Hurinionath referring to the house of Húrin the Steward in PM/202-3,218, and Gil-Galad's epithet Ereinion, cf. also the gloss of the old Qenya cognate yondo "descendant of" in PE/12:106, or the use of the same suffix in later Quenya names such as Isildurioni and Anárioni "Heirs of Isildur (resp. Anárion)" in PM/192,196