Where does “decathlon” come from?

decathlon (Italian) comes from Italian deca, from Latin decās, from Ancient Greek δεκάς, from Ancient Greek -ᾰ́ς, from Proto-Indo-European -ónts, from Hungarian önt, from Hungarian ön, from Hungarian ön- — sound, voice.

decathlon (Italian): decathlon

Definitions

decathlon

Ancestry of “decathlon”, step by step

Step	Language	Word	Meaning
1	Italian	deca	decade; a 10,000 lire banknote
2	Latin	decās	a decade (period of ten years)
3	Ancient Greek	δεκάς	the number ten; a group of ten, decade
4	Ancient Greek	-ᾰ́ς	group of
5	Proto-Indo-European	-ónts	Derives nouns denoting body parts
6	Hungarian	önt	to pour; to cast; accusative singular of ön
7	Hungarian	ön	you
8	Hungarian	ön-	self-
9	Turkish	ön	front
10	Ottoman Turkish	اوك	voice (of human or animal); sound
11	Proto-Turkic	ǖn	sound, voice

Every word from Proto-Turkic ǖn →Every word from Ancient Greek -ᾰ́ς →Every word from Hungarian ön- →