Examples from literature

• It is true that youth laughed—pale, animal boys, and pale, flat-chested girls. 
• She does not want to be muscular and flat-chested, nor, on the other hand, to be over-stout, but she prays for the flowing lines and the plumpness that belong to youth. 
• She was a tall, angular, high-shouldered, and flat-chested woman, dark from exposure to wind, sun, and rain, her hair brown in the neck, but many shades lighter on the crown of her head. 
• She was of medium height, thin and somewhat flat-chested. 
• Stretched over her long flat-chested figure, they seemed to acquire the consistency of armor.