1. in the sense of essential requirement
- prerequisite
- essential requirement
- essential
- indispensable thing/item
- necessary
- requisite
- basic
- fundamental
- desideratum
- sine qua non
- need
- indispensability
- needfulness
2. in the sense of inevitability
- unavoidability
- inevitability
- inescapability
- certainty
- ineluctability
- inexorability
3. in the sense of need
- need
- force/pressure of circumstance
- call
- obligation
- crisis
- exigency
- urgency
- emergency
- force majeure
Example Sentences of Necessity
1. Water is a necessity for survival.
2. Education is a necessity for success.
3. In emergencies, communication becomes a necessity.
4. Food and shelter are basic necessities.