Secondary sexual characteristic

A secondary sexual characeristic refers to any physical trait that can have an influence on sexual reproduction without directly impacting reproductive function itself.

These characteristics usually develop in a species during the journey to sexual maturity. In humans, for example, secondary sexual characteristics begin to develop during puberty, typically associated with hormone secretions.

Examples
Examples of a human secondary sexual characteristic include:

Men:
 * Facial hair
 * Vocal pitch
 * Muscular development

Women:
 * Development of the mammary glands
 * Pelvic structure (physical attraction, but also childbearing abilities)