necessary

adjective
UK /ˈnes.ə.sər.i/
US /ˈnes.ə.ser.i/

Something that is necessary is needed and you must have it.

Water is necessary for all living things.

SYNONYMS

neededrequiredessentialvital

RELATED WORDS

needrequirementnecessityimportant

OTHER MEANINGS

2. Something that cannot be avoided or done without.

It is necessary to wear a seatbelt in the car.

3. A thing that is needed for a certain purpose.

We packed all the necessaries for the camping trip.

4. Certain to happen or exist.

A little rain is necessary in spring.