1. Appropriateness of behavior or conduct; propriety: "In the Ireland of the 1940's ... the stolidity of a long, empty, grave face was thought to be the height of decorum and profundity" (John McGahern).

2. decorums The conventions or requirements of polite behavior: the formalities and decorums of a military funeral.

3. The appropriateness of an element of an artistic or literary work, such as style or tone, to its particular circumstance or to the composition as a whole.