From this site:
The word "dreidel" is a Yiddish word built on the German word drehen "to spin, turn." This word is related to English "throw," which originally meant "to turn or twist." Albanian tjer "I spin" as well as Latin torquere "to spin," whence our words "torque" and "torment," are also cousins.
In pottery, "to throw" still means "to turn":
the Old English word thrawan from which to throw comes, means to twist or turn. Going back even farther, the Indo-European root *ter- means to rub, rub by twisting, twist, turn. The German word drehen, a direct relative of to throw, means turn and is used in German for throwing. Because the activity of forming pots on the wheel has not changed since Old English times, the word throw has retained its original meaning in the language of pottery but has developed a completely different meaning in everyday usage. Those who say they throw pots are using the historically correct term.
How did throw go from "to turn, twist" into "to project, propel"? The Online Etymology Dictionary suggests that "the sense evolution may be via the notion of whirling a missile before throwing it."
As an aside - the original meaning of the "nun" "gimmel" "heh" and "shin" was not "nes gadol haya sham" נס גדול היה שם. The letters were rather:
a mnemonic for the rules of a gambling game played with a dreidel: Nun stands for the Yiddish word "Nichts" (nothing), hei stands for "Halb" (half), gimel for "ganz" (all), and shin for "steln" (put in).
The Yiddish, in turn, came from a German game, which had the letters N, H, G and S.