Motherfucker (sometimes abbreviated as mofo, mf, or mf'er) is an English-language vulgarism. While it is usually considered highly offensive, it is rarely used in the literal sense of one who engages in sexual activity with another person's mother, or his or her own mother. Rather, it refers to a mean, despicable, or vicious person, or any particularly difficult or frustrating situation. Alternatively, it can be a term of admiration, for instance in the jazz community.