ואמר הדור האחרון בניכם אשר יקומו מאחריכם... “And the generation to come, your children that shall rise up after you…”(Devarim 29:21, translation by the Jewish Publication Society).
If you ask any child learning Hebrew what the word אחרון means, he will tell you that it means last. For example, last in line, לאחרונה יסעו (Bemidbar 2:31), last in space and time, אני ראשון ואני אחרון (Yeshaya 44:6), and last chronologically, ויקרא...יום בים מין היום הראשון עד היום האחרון (Nechemia 8:18). Seemingly the word אחרון is either ambiguous in all instances or it can take on a number of meanings.
All three of the examples that I presented mention, either in that Pasuk or in a Pasuk nearby, the word ראשון. Therefore you might think that when the Pasuk gives a beginning the word אחרון must be an ending, and only in other situations is the word אחרון ambiguous. However this clearly can not be true, for the Pasuk in Chagai (2:9) states גדל יהיה הבית הזה האחרון מן הראשון... ובמקום הזה אתן שלם “The glory of this later house shall be greater than that of the former...in this place I will give peace” (JPS translation).” There are, however, those who interpret this Pasuk to be a reference to the final house, Bait Hamikdash Hashlishi, they therefore interpret the words הבית הזה as a reference to the end of the Pasuk, the house that will stand in this place.
It may seem from this explanation and the examples I have presented that for אחרון to mean anything other than last is very rare. However this is not the case. In all cases where the word דור is used preceding אחרון, the phrase is interpreted as “a later generation.” Other cases vary, for example when Hashem gave Moshe three signs to show the people (Shemot 4:8), Hashem refers to the second sign as אות האחרון, seemingly meaning the second (and therefore last) of the two already given. One of the borders of Eretz Yisrael given in Devarim 11:24 is הים האחרון “the hinder sea.” When the Chumash presents the process of stoning (Devarim 17:7) it says יד כל העם באחרונה, while literally it does mean that the nation was last, logically it means that they stoned afterward.
One final example of the ambiguity of אחרון is found in the Pasuk in Yeshaya (30:8) בוא כתבה על הלוח...ותהי ליום האחרון לעד עד עולם, “Now go, write it before them on a tablet…that it may be for the time to come for ever and ever.” The question here is of whether it should be read “until the last day,” or “for a later day.”