Eggcorn Forum

This came up on Merriam-Webster’s Word of the Day:

The etymology of the word posthumous tells a complex story. In Latin, posterus is an adjective meaning “coming after” (from post, meaning “after”). The comparative form of posterus is posterior, and its superlative form is postumus, which means, among other things, “last.” Postumus had specific application in referring to the last of a man’s children, which in some cases meant those born after he had died. Latin speakers incorrectly identified the -umus in this word with humus, meaning “dirt” or “earth” (suggesting the ground in which the unfortunate father now lay). The Latin spelling became posthumus, as if the word were formed from post and humus , and both the “h” and the suggestion of “after burial” or “after death” carried over into English.

I don’t think we’ve looked at this transformation of “posthumous” on the Forum. The spelling switch from “postumus” to “posthumus” under the influence of a mistaken etymology would make it an eggcorn-but a Latin eggcorn (a “caunea”) since the transformation had already happened before the word was assimilated into English.