Definitions:

1. basic and fundamental adjective
   • the essential feature
2. being or relating to or containing the essence of a plant etc adjective
   • essential oil

Synonyms:

• all important
• all-important
• crucial
• indispensable
• necessary
• necessity
• of the essence
• requirement
• requisite
• substantive

NearBy Words:

• essentiality
• essentially
• essentialness