While the terms "obscene," "profane," and "vulgar," etc., are often used synonymously for what otherwise is referred to as "cursing," there are distinctions among these terms:

1. "Profanity" involves a religious distinction. To be profane is to act (or speak) outside the conventions of religious belief, including ignorance or the appearance of indifference toward religious concepts, such as by saying "Jesus H. Christ, let's get the hell out of here!" or "Doesn't the rabbi shit like the rest of us?"

2. "Blasphemy" is closely related to profanity. While profanity reflects an ignorance or indifference to religious matters, blasphemy purposefully shows disrespect or disdain for religion or religious concepts. Examples would include "To hell with the fucking pope, I'll use birth control if I want to!" or even just "religion sucks!"

3. "Epithets" are "brief, forceful bursts of emotional language" (Jay) — what we yell when we stub our toes, or do "something stupid or frustrating." They tend to be spontaneous, stand alone, and are typically directed at no one in particular. Examples are "damm it to hell!", "Shit, shit, shit!!" or other expletives we all frequently hear (and no doubt use ourselves) when something suddenly goes badly wrong.

4. "Vulgarity" is the use of common, uncultivated, crass or coarse language. It is thus contextually or situationally-based. Vulgarities are not necessarily "obscene" or even "taboo", but would be considered "in poor taste" in a particular situation. A guest at a formal dinner who tells an off-color joke, or comments that the hostess' special sauce looks to him like "snot," would be using vulgar language.

5. "Taboo" or "forbidden" words are those that, within particular societies or social contexts, are stigmatized. They are not necessarily "vulgar," as they may match the register of a particular discourse. Language taboos are not necessarily even cursing; most sports have situations, such as in baseball when a pitcher is close to completing a "no-hit" performance, when tradition says that teammates must not say anything relating to the performance in order not to "break the charm." More generally, one thinks of H.C. Andersen's story "The Emperor Has No Clothes" for examples of when people feel there are reasons why they cannot describe something as it actually appears to be.

   To use forbidden words is "risky," defying social convention and almost inviting retribution. Thus, when used, they may reflect considerable emotion, disregard of the consequences, and possibly even loss of rational control. Most forbidden words have a variety of euphemized forms that are (more) acceptable (such as "gol darn" instead of "God damn!"). In the U.S., for a male to call a female a "cunt" would be taboo, although in Britain the word is far less stigmatized.

6. "Slurs" are insults which are usually racial or ethnic in nature, though they may also be gender-based. For a white to call a black a "nigger" is a racial slur. Referring to Italian-Americans as "dagos, spics and wops," or to Jewish-Americans as "kikes or yids" would be ethnic slurs. Referring to women as "raggy bitches" would be a gender slur.

7. "Obscenities" are perhaps the most problematic category, as this refers to terms which are unprotected by laws or legal concepts regarding freedom of speech (although the term "obscenity" is often used in a general sense for "profane" or "forbidden" language, rather than just its technical sense). These legal concepts will vary widely both within and between different countries and variants of English.

The U.S. Supreme Court has designated five categories of unprotected speech, one of which is obscenity. However, the definition of "obscenity" is elusive. The current legal definition is based on a "three-prong test" from Miller v. California (1973), each prong of which must be met in order for language to be defined as obscene:

1. The average person, applying contemporary community standards, would find that the work, taken as a whole, appeals to a prurient (lewd, lustful, tending to incite lust, etc.) interest;

2. The work depicts or describes, in a patently offensive way, sexual conduct which specifically defined by the applicable state law (such as bestiality or pedophilic actions, or sodomy in some states, but more recently possibly even gay marriage in some states);

3. The work, taken as a whole, lacks serious literary, artistic, political, or scientific value.

A great many things may be covered by prongs A and B; most of the many legal cases which have challenged standards of obscenity (or "decency") have involved varying definitions of prong C — the terminology of which itself is open to considerable interpretation.