1. the quality or state of being essential; the fundamental or indispensable nature of something
Usage: formal; often used in philosophical or technical contexts
2. an essential element or feature; something that is absolutely necessary
Usage: often used in plural form

Examples

• The essentiality of clean water to human survival cannot be overstated.
• Philosophers debate the essentiality of consciousness in defining personhood.
• The company identified the essentialities needed to launch the product on time.
• Understanding the essentiality of proper nutrition is key to good health.
• The essentiality of teamwork became clear during the crisis.
• She questioned the essentiality of all the new regulations.