Pronunciation: [kˈa͡ɪstəz] (IPA) 
The word "keisters" is commonly misspelled as "kiesters" or "keestors". The correct spelling is /ˈkiːstərz/ and it refers to a slang term for buttocks. The spelling reflects the pronunciation, with the long "ee" sound from the "ee" digraph and the final "s" sound to indicate the plural form. The word has been in use since the early 1900s and has various spellings, but "keisters" is the most commonly accepted spelling.
Keisters, as a plural noun, refers to the large muscles of the buttocks, commonly known as the buttocks or the derriere. It is primarily a slang term used mainly in informal conversations. The term "keisters" is often employed in a light-hearted or humorous manner when referring to the posterior region of the human body.
The word itself likely originates from variations of the word "kiste," a now-archaic term derived from the Dutch language that means "chest" or "coffer." "Keisters" may have derived from the early 20th century slang term "kiester," which referred to a suitcase or bag, possibly alluding to the rounded shape of both a bag and the buttocks.
In contemporary usage, "keisters" is primarily used to refer to the anatomical area in a non-offensive or playful manner. It is often employed in casual conversations, comedy sketches, or light-hearted discussions, particularly when discussing body parts with a tinge of humor or to alleviate potentially sensitive topics.
However, it is crucial to acknowledge that slang and colloquial terms like "keisters" are context-dependent and may not be appropriate in formal or professional settings. It is important to exercise discretion and awareness when using such terms to avoid offending or disrespecting others.
The word "keisters" is believed to have originated in the United States in the early 1900s. It is thought to be a slang term derived from the German word "kiste", meaning "box" or "chest". Over time, "kiste" transformed into "keister" in American English, referring to a suitcase or trunk. Eventually, the term began to be used to describe a person's buttocks or backside, possibly drawing a comparison between the shape of a trunk and that part of the body. "Keister" is predominantly used in informal language and is considered a colloquial or slang term for buttocks.
