Spanish profanity

The Spanish language employs a wide range of swear words that vary between Spanish speaking nations, and in regions and subcultures of each nation. As in most languages swear words tend to come from semantic domains considered taboo such as the domains of human excretions, sexuality, and religion. As in most languages, in Spanish swearing serves several functions in discourse, as emphatic interjections expressing emotion, as expressions of interpersonal stances such as aggression or as expression of gender identity, and as forms of linguistic play.

Spanish insults are often of a sexual nature, taking the form of implying a lack of sexual decency if the insulted person is a woman (e.g. puta, ramera "whore", perra "bitch") or implying a lack of masculinity if the insulted person is male (e.g. maricón "faggot", puto "male prostitute"). A particularly forceful Spanish insult is any mention of someone else's mother, (called mentar la madre), including also in its strongest form insinuations or mentions of sexual relations (e.g. ¡chinga tu madre! "fuck your mother!").

Emphatic exclamations, not aimed to insult but to express strong emotion, often include words for sexual relations (e.g. ¡joder! "fuck!", ¡chingados! "fuckers!") or to excretions or sexual organs (¡mierda! "shit!", ¡carajo! "penis!"). Sexual taboo words that describe a masculine sexuality may be used in a positive sense (e.g. cabrón "male goat", gallo "rooster", chingón "fucker").

Pendejo (according to the Diccionario de la lengua española de la Real Academia Española, lit. "a pubic hair') according to the Chicano poet José Antonio Burciaga, "basically describes someone who is stupid or does something stupid." Burciaga said that the word is often used while not in polite conversation.Pendejo is equivalent to the English expression dumb-ass, which literally means, "as dumb as a donkey".

Burciaga said that pendejo "is probably the least offensive" of the various Spanish profanity words beginning in "p", but that calling someone a pendejo is "stronger" than calling someone estúpido. Burciaga said "Among friends it can be taken lightly, but for others it is better to be angry enough to back it up." In Mexico, "pendejo" most commonly refers to a "fool", "idiot" or "asshole". In Mexico there are many proverbs that refer to pendejos.

...
Wikipedia