The word “meh” can be used in several ways, but it is usually used to indicate that the subject is of little interest. It can also be used to indicate frustration, agreement, or disagreement. Though it started out as a multipurpose vocal utterance to indicate boredom, displeasure, or dissatisfaction, it has popularized and changed in use and can now appear as a descriptive adjective. It is often interchangeable with words like "whatever" and "eh." In some uses, it is related to “bah," but lacks the inherent negative connotation, dismissing the subject with apathy rather than anger.
Generally, this word is used only in informal conversations, though some writers have used it in newspapers and publications. In informal text chat, “meh" can be used to describe something slightly negative, particularly something that did not meet expectations. A concertgoer might say “I thought the Pumpkins were going to put on a good show, but it was really meh." The question “How was school?” might be answered “Meh," which generally communicates that the school day was boring and otherwise uneventful.
The meaning of this word depends heavily upon the context and tone in which it is spoken. It can be a quick utterance or a protracted expressive sound. An apathetic meh can indicate mild agreement with the question at hand. When spoken in an aggressive or insistently whiny tone, it can indicate strong disagreement with the subject or a desire for the target of the utterance to leave. Some people also use the word, spoken slowly and softly, to indicate a dejected sadness, the word "feh" is by nature better suited for expressing negativity or sadness.
Although this word can be used to indicate apathy, it can also be used to feign apathy or provide a response in lieu of a direct answer to a somewhat sensitive query. Sometimes, the word “meh" can be used in place of a negative answer if the speaker does not want to indicate a strong negative response to the question. For instance, the question “Do you want to go on a family camping trip?” could be answered “Meh" if the speaker would like to avoid the camping trip but does not want the fallout that comes with a negative response. To further the confusion, the word can also be used to cover inappropriately excessive excitement or emotion. For instance, when asked how he feels about scoring well on a test, an answer of “Meh" may indicate that the speaker is pleased with his performance but does not want to appear to care.