1530s, verbal noun from nurse (v.) in any sense. Specific meaning "profession of one who nurses the sick or injured" is from 1860 (Florence Nightingale).
Entries linking to nursing
nurse v.
1530s, "to suckle (an infant), nourish at the breast;" 1520s in the passive sense, "to bring up" (a child); alteration of Middle English nurshen, norishen "to supply with food and drink, feed; bring up, nurture" (c. 1300; see nourish), in part by influence of nurse (n.1). From 1540s as "promote growth or vigor in, encourage." Sense of "tend to in sickness or infirmity" is recorded by 1736. Related: Nursed; nursing.