Profane Vulgarity and Swear Words

The words vulgar and profane are often used interchangeably, but they each have a distinct meaning. We can be excused this minor infraction, because dictionary definitions for each word almost always reference the other. I did some research in the pursuit of clarity, and here is what I came up with.

Vulgarity

I remember as a young man seizing upon a book in an Asuncion bookstore with the title “Canciones Vulgares,” which means in English “Vulgar Songs.” My glee at the prospect of expanding my musical repertoire to the seamier side of The Castilian was deflated upon learning that the title employed the more traditional use of the word. It was a book of indigenous folksongs expressed in the local vernacular rather than formal Academia Real Spanish.

vul·gar
adj.
1. Crudely indecent.
2.
a. Deficient in taste, delicacy, or refinement.
b. Marked by a lack of good breeding; boorish. See Synonyms at common.
c. Offensively excessive in self-display or expenditure; ostentatious: the huge vulgar houses and cars of the newly rich.
3. Spoken by or expressed in language spoken by the common people; vernacular: the technical and vulgar names for an animal species.
4. Of or associated with the great masses of people; common.

Here’s some interesting history on the word vulgar from The Free Dictionary:

The word vulgar now brings to mind off-color jokes and offensive epithets, but it once had more neutral meanings. Vulgar is an example of pejoration, the process by which a word develops negative meanings over time. The ancestor of vulgar, the Latin word vulgaris (from vulgus, "the common people"), meant "of or belonging to the common people, everyday," as well as "belonging to or associated with the lower orders." Vulgaris also meant "ordinary," "common (of vocabulary, for example)," and "shared by all." 

 An extension of this meaning was "sexually promiscuous," a sense that could have led to the English sense of "indecent." Our word, first recorded in a work composed in 1391, entered English during the Middle English period, and in Middle English and later English we find not only the senses of the Latin word mentioned above but also related senses. What is common may be seen as debased, and in the 17th century we begin to find instances of vulgar that make explicit what had been implicit. Vulgar then came to mean "deficient in taste, delicacy, or refinement." From such uses vulgar has continued to go downhill, and at present "crudely indecent" is among the commonest senses of the word. (TheFreeDictionary.com)

Profanity

profane
adj
1. having or indicating contempt, irreverence, or disrespect for a divinity or something sacred
2. (Christianity / Ecclesiastical Terms) not designed or used for religious purposes; secular
3. (Christianity / Ecclesiastical Terms) not initiated into the inner mysteries or sacred rites
4. vulgar, coarse, or blasphemous profane language

So profanity is more of a taking The Lord’s name in vain or speaking irreverently about sacred things, while vulgarity is broader and includes speech that is boorish, distasteful, obscene or otherwise offensive. Bathroom humor, slang terms for human activity and body parts, swear words and so forth are more properly classified as vulgarities rather than profanities.

Swearing, Cussing and other Expletives

To swear has always meant to take an oath, but it now has negative connotations as well: swear words, swear at…

The secondary sense of "use bad language" (early 15c.) developed from the notion of "invoke sacred names." Swear-word is Amer.Eng. colloquial from 1883. (Online Etymology Dictionary)

For a quick history on “cuss” (probably came from curse) and “expletive,” as well as a short history on the the F-Word, see the Online Etymology Dictionary.