AUTUMN, AUTUMNUS and... Latin OTIUM - 'rest, repose, peace, quietness'

[new_etymology]

AUTUMN (Eng.), autunno (Ital.), otoño (исп.), autono (Port.), autumnus, auсtumnus (Latin) - autumn - is allegedly a word 'of unknown origin' (as thousands of others, accroding to Indo-Europeists): https://www.etymonline.com/word/autumn .

Is it really 'unknown'?

To establish the etymologic connections for AUTUMN (as well as for the Russian ОСЕНЬ, Church Slavic IЕСЕНЬ), it may be necessary to first of all make comparisons to words with the semantics of "delaying, waiting / commencement of the quiet, silent waiting time" (and not disregard the obvious connections to the Finno-Ugric and Turkic languages):

OOTA(MA), ooda(ta) (Estonian), odottaa (Finnish), vȯ’dlõ (Livonian), ådsotet (Lappish), oottaa (Votic), oodella (Izhorian) - to wait, await;
vait (Est., Votic), vaiti (Fin.), vaid (Izhor.), vaitti (Vepssian), váidut (Lappish) - quiet, silent; quietly, silently;
vuottua (Karel.), vottata(da) (Veps.), vȯ’dlõ (Livon.) - to wait, await;
viťi̮(ni̮) (Udmurt), видзчисьны [vidzchis'(ni)] (Komi-Permian) - to wait;
βuč́aš (Mari), učo(ms) (Erzia), učǝ(ms) (Mokshan) - to wait;
WAIT (Eng.)[Spoiler (click to open)] - considered to be in the semantic field of Ger. WACHT, WACHTEN - "to watch, to guard" - which is obviously a part of the following further semantic field (or sub-field):

> week (Eng.), Woche (Ger.), vekka (Sw.) - week;
> век [vek] (Rus.) - time, era; веха [veha] (Rus.) - a milestone, a finished period;
> [waqt] (Arab.) - time;
> vakit (Turk.), vaxt (Azeri), vaqt (Uzb.), уақыт [vakhyt] (Kaz.), убакыт [ubakyt] (Kyrg.), вақт [vakht] (Tadzh.) - time;
> vecchio (Ital.) - old, elder (i.e., 'aged', 'timed');
> vég (Hung.) - the end; végzet (Hung.) - the fate;
> végr, végre (Hung.) - in the end;
> vakare (Lithuanian) - evening; vakaruose (Lith.) - West;
> вечер, vecher (Slavic) - evening; N.B. close to, but unlikely a direct derivation from the Gr. ἑσπέρα, Latin vesper, vespera, vesperum - evening; west; esperare (Sp.) - to wait; sperare (It.) - to hope. Could similarly be indirectly related to vestr (Old Norse), vestur (Icelandic) - west, the sunset side.
See: https://new-etymology.livejournal.com/15774.html

ootavalt (Est.) - expecting, waiting, being waiting;
otaviti sе (Czech, according to Max Vasmer) - to relax, to gain strength;
ота́ва, otava, otawa, wotawa (Slavic) - an unmown grass in a meadow that rests under snow until spring: https://eesti-keel.livejournal.com/168287.html :


1отеа, 1атина-сатий [(h)otea, (h)atina-satiy] (Ingush) - settled down, laxed, quiet;
OTIUM (Latin) - rest, repose, peace, quietness;
ATUM, ATOUM, ATEM, TEM (in ancient Egyptian mythology) - the god of pre-existence and post-existence; in the solar cycle is associated with sunset;
AUTUMN (Eng.), autunno (Ital.), otoño (исп.), autono (Port.), autumnus, auсtumnus (Latin) - autumn.

Compare further to:
ÖÖ (Est., Votic, Izhora), īe (Livon.), yö (Fin.), üö (Karel, Ludic), ö (Veps.), ve (Erzia., Moksha), uj (Udmurt), voj, oj (Komi), jǝj, ǝj (Khanty), jī (Mansi), éj (Hung.) - night;
õhtu, ehtu, ohtu, õdang (Est., Izhor.), õdak, õtak (South Est.), ȭ’dõg (Livon.), õhtago, õhtogo (Votic), ehtoo (Fin.), ehtü (Karel.), eht (Ludic, Veps.) - end of the day, evening, sunset, west;
Ithaca (according to Homer, "an island looking into the night");
eha (Est.) - the evening glow;
ikte (Lppish) - yesterday;
jüt (Mari) - night;
ǖtə (Sekulp.), jetn̥ (Khanty) - evening;
ēt (Mansi) - evening, night.

See also:
итог [itog] (Rus.) - final total, summ (per Max Vasmer, allegedly from "и" + "того" - which is doubtful).

Compare to words with n-:
ńüde (Mator language of the Samoyedic group) - evening;
nox, noctis (Latin), νύξ, νυκτός [nix, niktoc] (Gr.) - night, darkness;
night (Eng.), Nacht (Ger.), [nakta] (Sanskrit.), notte (Ital.), Noche (Sp.), ночь [noch'] (Rus.), etc. - night;
nichts (Ger.) - nothing, nothingness.
See https://anti-fasmer.livejournal.com/282197.html

Compare also to:
หยุด [H̄yud, yut] (Thai) - stop, wait;
காத்திரு [Kāttiru] (Tamil.) - to wait, await;
kut(moq) (Uzbek.), күту [kütu] (Kazakh) - to wait, await;
көз (Tatar), güýz (Turkmen), kuz (Uzbek), күз (Kazakh, Kyrgyz) - осень [osen'] (Rus.) - autumn;
қыс (Kazakh), кыш (Tatar, Kyrgyz), gyş (Turkmen), kış (Turkish), qish (Uzbek) - winter;
кышлак, кишлак, kishlak - not just 'a village', but 'the winter camp' of the nomad peoples;
N.B. noteworthy is the use in the Turkic languages of practically the same word for autumn and winter - literally, the "waiting time";
gēide (Prussian) - 'they wait';
ГОДИТЬ [GODIT'] (Rus.) - to wait, await.

Compare further to:
кад, kad (Komi-Permian) - time;
ГОД [GOD] (Rus.) - calendar year;
година [godina] (Ukr.), godzina (Pol.), hodina (Czech) - hour.

Did you know that all of these words are related (and above is just a little part of their relations)? Or does one prefer to continue to believe that most of these words 'self-developed', had to have some hypothetic PIE stem before being compared to the non-IE languages, and most are 'of uncertain' or 'of unknown' origin, as the Oxford Etymological Dictionary (OED) still tries to convince us?