replacement Definition

the action or process of replacing : the state of being replaced

one that replaces another especially in a job or function

a set of elements any one of which may be used to replace a given variable or placeholder in a mathematical sentence or expression (such as an equation)

therapy involving the supply of a substance (such as a hormone or nutrient) lacking in or lost from the body

hormone replacement therapy involving the administration of estrogen without progestin

the therapeutic use of hormones typically to increase diminished levels in the body : hormone therapy; especially : the administration of estrogen often along with a synthetic progestin especially to ameliorate the symptoms of menopause and reduce the risk of postmenopausal osteoporosis —abbreviation HRT