Is 長 in Japanese related to “naga” in Thai and Sanskrit?

Question

The kanji 長い (“nagai”) means “long” in Japanese.

And “naga” in Sanskrit and Thai means “snake” or “serpent”.

It seems to me that there could be a relation between them given that snakes are usually described as long.

Is there any relationship between them? Do they have a shared origin?

Answer 1

One could extend that hypothesis to ask if there's a connection between English long and Yiddish schlong.

• English long ultimately derives from Proto-Indo-European *dlongʰos (“long”).
• Yiddish schlong is from German Schlange ("snake") and ultimately derives from Proto-Indo-European *slenk- (“to wind, twist, slink, creep”).

That is, no apparent connection.

Back to your particular thought:

• Japanese 長- naga- is thought to derive from, or be cognate with, obsolete verb 流る nagaru, root of modern verb pair 流れる nagareru ("to flow") / 流す nagasu ("to flush something, to make something flow"). I've also thought these might be related to verb 投ぐ nagu, modern 投げる nageru ("to throw").
• Sanskrit नाग naga ("snake") ultimately derives from Proto-Indo-European *sneg- (“to crawl; a creeping thing”), the same as English snake.

So again, no apparent connection.