The compositor for the 1841 British edition accidentally set word as world, perhaps under the influence of the following would. This obvious typo was removed from the following 1849 LDS edition (even though it used the 1841 edition as copytext). In two other places the text refers to the word being void (the first is only a few verses later):
Summary: Maintain in Alma 12:23 the reference to the word, not the world, as being void.