Today's word

An interesting Words at Play post on the increasingly rare use of "soever" words led to an interesting new word:

tmesis /(tə-)ˈmē-səs/ - separation of parts of a compound word by the intervention of one or more words (such as what place soever for whatsoever place)

I can't help but wonder if the insertion of words in the middle of a common phrase - such as "shut up," which people frequently divide by insertion of a two-word expletive beginning with the definite article - is also considered tmesis, or merely vulgar.