Definition of Nurse by Merriam-Webster

ˈnərs

1a

: a woman who suckles an infant not her own : wet nurse

b

: a woman who takes care of a young child : dry nurse

2

: one that looks after, fosters, or advises

Time is the nurse and breeder of all good.— Shakespeare

3

: a person who cares for the sick or infirm

specifically

: a licensed health-care professional who practices independently or is supervised by a physician, surgeon, or dentist and who is skilled in promoting and maintaining health — compare licensed practical nurse, registered nurse

4a

: a worker form of a social (see social entry 1 sense 4b) insect (such as an ant or a bee) that cares for the young

b

: a female mammal used to suckle (see suckle sense 1a) the young of another

a nurse cow

transitive verb

1a

: to nourish at the breast : suckle

b

: to take nourishment from the breast of

3a

: to promote the development or progress of

b

: to manage with care or economy

nursed the business through hard times nursed a 1–0 lead

c

: to take charge of and watch over

4a

: to care for and wait on (someone, such as a sick person)

b

: to attempt to cure by care and treatment

5

: to hold in one’s memory or consideration

nurse a grievance

6a

: to use, handle, or operate carefully so as to conserve energy or avoid injury or pain

nurse a sprained ankle

b

: to use sparingly

c

: to consume slowly or over a long period

nurse a cup of coffee

intransitive verb

1a

: to feed an offspring from the breast

b

: to feed at the breast : suck

2

: to act or serve as a nurse

ˈnərs

Sir Paul Maxime 1949– British geneticist

Source