‘Side boob’ describes the side of a female breast showing at the edge of clothing that is cut low, loose or backless, rather than any deliberate display down the front. It is almost always used about photographs of celebrities on red carpets or at events, where a dress gapes or a top’s armhole sits further back than expected. The phrase is casual and often used in a knowing, gossipy way, as part of the wider vocabulary that grew up around paparazzi and tabloid coverage of what women wear and how much of them is on show.
What’s the origin of the phrase ‘side boob’?
The term belongs to a small family of compound phrases built on “boob” that name particular angles of exposure, sitting alongside “under boob” and “inner boob” for other parts of the breast that might be glimpsed through gaps in clothing. This suggests the coinage grew out of a general habit of labelling these moments rather than any single deliberate invention.
One of the earliest traceable uses online was in January 1997, when a woman posting in a boxing discussion group on Usenet described her husband noticing a “side boob shot of the ring girl.” In print, the phrase turns up in Christina Bartolomeo’s 2002 novel The Side of Angels, its first known appearance in a book. From there it moved into the language of celebrity gossip, helped along when it was added to Urban Dictionary in 2005, a point at which slang terms of this kind tend to become fixed in wider use.
Through the mid-2000s the phrase became a regular fixture of tabloid and magazine coverage, with Lindsay Lohan frequently mentioned in connection with it during that period. Public interest in the term, judged by search activity, is said to have peaked in 2017, a time when photographs of Selena Gomez and Kendall Jenner at public appearances were widely discussed under the label. By then “side boob” had settled into ordinary use as a fairly neutral, if slightly leering, description rather than a novelty term, and it is defined plainly as the side of a female breast revealed by skimpy clothing. Its history is really the history of paparazzi photography and red carpet fashion commentary as much as it is the history of a single phrase, and no earlier printed use than the 1997 Usenet post and the 2002 novel has been traced.