Silhouette
Definition
The term silhouette refers to the outline of an object. In fashion, it is used to discuss how clothing affects the perceived shape of a person. Silhouettes can range from deathly slim to relaxed and baggy. No silhouette is inherently better or worse, but you should always be aware of what you are trying to achieve. Wanting a thin silhouette isn't an excuse for buying everything as tight as possible, and wanting a loose silhouette doesn't mean you should look like a slob and wear XL tees. Pay attention to fit.
Examples
Dropcrotch vs Normal Crotch
The image on the right shows the difference between the silhouettes of dropcrotch and normal sweatpants.
Small vs Large Toeboxes
The image on the left shows the difference between large and small toeboxes. Red Wing Mocs are notorious for their large toeboxes, which tend to cause shoes to be called "clown shoes", because of the large toeboxes of clown shoes. The image below demonstates the difference between small and large toeboxes.
External Links
https://en.wikipedia.org/wiki/Silhouette#Fashion_and_fitness
http://www.fashion-era.com/C20th_costume_history/1940s-silhouettes-dresses-1940-1949.htm