In English, blah is a word that is sometimes used as an expression for words or feelings where the specifics are not considered important to the speaker or writer for emotions. It is not often seen in formal writing, except when transcribing speech. It differs from a speech disfluency such as "um" or "er" in that blah is a word used deliberately to represent other words, rather than as an accidental or temporary interjection into speech. Blah is also used when the speaker cannot say what was intended. "Blah" is also mimed behind people's backs to suggest that they talk too much or that they talk about useless topics for no reason. The word "Blah" can also be used in a mocking or sarcastic tone. "Blah" can also be used as a sign of impatience and arrogance towards another.
"Blah" is a token word with no meaning of its own, usually used to illustrate generic, boring speech. It may be used to fill in blank space, or to replace another word or phrase. It's for this last purpose that blah is sometimes assumed to mean something negative because it is used to replace a word that may be unpleasant, but blah itself is neutral. If spoken aloud the tone can usually be used to determine the speaker's intent.
"Blah" is also used within a compound noun, suggesting a psychological state or expressing an opinion; for example, February blahs describes a generally depressed condition during winter. It is also viewed as a word expressing indifference, or lack of a preference. It may also be used to imply that something is not impressive, or it is boring, bland, or without character.
Several alternatives or variants of the word can be observed today, such as bleh, blech, bla, meh or bah, although some differences may be perceived in certain contexts. Generally these variants would only be used in place of blah to show unimportance, disgust or disinterest. The word used is typically left to individual preference.
The word likely originated as an echoic, or onomatopoeia, representing a block of speech that is drawn out, boring or vacuous enough, so that all that is heard is the repetition, "blah, blah, blah".
Historically similar, echoic, and potentially influential words include:
Wine, Women, and War, a 1918 journal of Howard Vincent O'Brien (Jul 11, 1888 - Sep 30, 1947) covering World War I and published in 1926, is one of the first known publications to use the word.
The sociolect variety that has been emerging in Internet culture has further fueled the popularity and diversity of this word. As of September 15, 2008, a search in the Google search engine results in 36.8 million hits or 70.4 million on the Yahoo search engine .
Blah is a commonly used word in the world of slang.