When viewed from the side, if you can see the crease under the breast where it returns to the torso while the nipple is still concealed, you are seeing Sideboob.
Whereas Navel-Deep Neckline is all about showing as much of the area between the breasts as possible, this trope is about exposing the outer sides, roughly from the armpit to the nipple. There is a variant where the nipple is intentionally concealed by the arm, the hand, or the legs, and occurs frequently in topless fashion photography.
Bonus points if combined with Navel-Deep Neckline. A staple aspect of Vapor Wear. Commonly goes hand in hand with Naked Apron, though not at all restricted to it. Compare with Underboobs.
Examples:
- Allegory of the Four Seasons (Manfredi): Summer is looking at the viewer over her shoulder. Since she is bare-chested, the side of her boob is in full view, bare nipple included.
- Bleach: Yoruichi's backless suit during her fight with Soifon sports this. Not to mention Kuukaku's outfit.
- Nico Robin in the seventh One Piece movie briefly sports a gorgeous blue dress which contains some side boob.
- Sakura from Tokkô shows some side boob through her tank-top in a few scenes.
- In the original Yu-Gi-Oh!, Mai's Harpie Lady monsters wear what is little more than a slingshot bikini.
- Machete: Agent Santana Rivera has the naked variant in her Shower Scene.
- In American Reunion, Stiffler excitedly points out that he can see this when ogling an attractive girl in the beach scene.
- On an episode of The Late Show with David Letterman, the audience (and later all of Manhattan via the Jumbotron) gets a quick shot of Drew Barrimore's side boob, while Birthday Boy Letterman gets to enjoy the full effect.
- During his review of Q2, SF Debris refers to "television sideboob" regarding Jeri Ryan's nude scene.
- Blue Peter presenter Zoe Salmon became the first BP presenter to go topless in the history of the show, and quite possibly the history of BBC childrens' broadcasting. This wasn't even with any high-minded purpose, such as education or art. The presenters were reproducing iconic images from the James Bond movies and Zoe did the one where the girl is covered in gold paint. Zoe was topless in sideboob pose and a combination of hair and right arm covering the contentious bits.
- Morrigan's starting outfit in Dragon Age: Origins demonstrates sideboob. Ditto her uber-clothes that you get for completing her personal quest.
- In The Elder Scrolls V: Skyrim, there are a few outfits. The most noticeable is the Ancient Nord Armor, Action Girl Aela the Huntress wears. Later on in a certain guild quest line, the Player if playing a female character can craft the same armor. It is also seen on draugr that were once women in life.
- In Resident Evil 6, Sherry Birkin gets captured by N.G.O. Superpower Neo-Umbrella. Six months later she wakes up in a Stripperiffic patient's outfit that includes this.
- In God Eater Burst, Sakuya's spaghetti-strap crop top leads to this look.
- Higurashi: When They Cry: Hanyuu has one on a splash page of the manga-adaptation.
- Gaap from Umineko: When They Cry is missing the sides of her dress.
- In a Karate Bears dream sequence, a lady with sideboob rides bareback.
- The Whiteboard: As part of the 2012 April Fools' Day comic, the audience is treated to a Shower Scene with Pirta, who's turned so that only the side of a breast is showing, with fur covering other details of her nudity.