What does "the infelicities of language" mean ? Infelicities means "inappropriate and unpleasing manner or style". So, is the phrase "infelicities of language" a euphemism for curse words ? Or is the phrase a euphemism for vulgar language ? Or does the phrase "the infelicities of language" mean something other than what I have suggested ?
It can mean many things depending on context:
awkward diction or phrasing, using words from different registers in the same sentence
questionable grammar/semantics (not outright solecisms)
blunt or jarring style (eg false parallelism or ambiguity from removing parallelism)
I wouldn't call vulgarities themselves infelicitous unless used in the middle of a poetic or formal discourse.
I believe it is used to refer to imprecise language, not adequately or clearly expressing a thought or idea, either due to the nature of language in general, or to ineptitude on the part of the speaker. Here are some examples:
Imperfect, too, in fairness - Rowling calibrated her prose carefully in "The Casual Vacancy", as if to show she could do it, but her old infelicities of language have returned. -- The lady has a past, quoted in thefreedictionary.com
Infelicities of language, whether in the spoken or written word, were identified and assailed by a great many people who seemed to believe that the English language itself was in a period of decline -- Language Topics: Essays in honour of Michael Halliday, Volume 2
Assuming that Dr. Hodge refers to what the general assembly meant, and not to any mere infelicities of language... -- The Presbyterian Review, Volume 3