> -(i)stan (-i- is secondary here) goes back to Iranian *sta:na-
'site, abode' < *stah2-no- 'state, standing, position' (cf. Skt.
stHa:na-, Polish stan). It comes from the root *stah2-, from which
Eng. stand (stood) is also derived. English stone comes from OE sta:n
< PGmc. *stainaz. This in turn seems to be analysable as *stah2-ino-
(cf. Slavic ste^na 'wall'), meaning something fixed or solid. The
words may be ultimately related (though there are alternative analyses
of the "stone" etymon), but the connection is in either case far less
direct than the superficial similarity of forms might suggest.
>
> Piotr
A wide variety of words are said to derive from this, among them
English (via French from Latin) 'state', meaning state, country,
geopolitical unit.