The spelling of the word "post-ilions" can be confusing due to its combination of prefixes and suffixes. The first part of the word, "post-", means after or following, while the second part, "-ilions," is derived from the French word for million. The correct pronunciation is pohst-IL-yuns, with the stress on the second syllable. It is important to pay attention to the correct spelling and pronunciation of words to avoid confusion in written and spoken communication.