The phrase "triangle cutouts" refers to shapes that have been removed or cut out from something, creating triangle-shaped holes or openings. Full definition
The back has a small triangle cutout and a tie (see online product for a better idea) that makes for a casual, but still sexy day dress. (fashables.com)
In a bronze DSquared2 gown with eye - catching triangle cutouts at the bodice and perfectly - matched Casadei heels, the actress hits the opening night after party of her Broadway play You Can't Take It With You in N.Y.C. (people.com)
In real life, the seamstress did not understand what I was going for and I ended up going to prom in a periwinkle dress with triangle cutouts. (gnomelover.com)