Philosophy word 'Holon'(in English) is translated to 'ὅλον' in Greek as the wikipedia page says.
On the other side, 'Whole'(in English) is also tanslated to ὅλον at Aristotle's Metaphysics.
Philosophy world 'Holon' (in English) is apparently different from 'Whole'; Holon means both whole and part simultaneously.
I wonder how Arthur Koestler's books about Holon are translated into Greek to differentiate 'holon' from 'whole'.
"A holon (Greek: ὅλον, from ὅλος, holos, 'whole' and -ον, -on, 'part') is something that is simultaneously a whole in and of itself, as well as a part of a larger whole." Thus sayeth Wikipedia. But this is nonsense. "Holon" is the neuter singular of "holos"; it means "a whole thing".
This is perhaps also of interest: How should particle names ending in -on be treated in Latin?
fdb's answer is entirely correct, but to put it another way:
The word ὅλον (holon), in Ancient Greek, just means "whole"—specifically the neuter singular nominative or accusative form. It's a pretty common word and has nothing to do with simultaneously being a part.
Arthur Koestler then used the word for a very different meaning in his books, writing in English, millennia later. But this is an English usage, not an Ancient Greek one. It's somewhat like how the Latin word id just means "it", not the primal instincts buried in the human psyche, or the Greek word ἤλεκτρον (ēlectron) means "amber" or "electrum", not a subatomic particle. Taking an Ancient Greek or Latin word and giving it a new, specific, technical meaning is a long and glorious tradition—and it's generally less confusing than repurposing an English word that the audience will already have in their mental lexicon.
