principal
1 of 2adjective/ˈprɪnsəpəl/
1
having the highest importance or influence
B2- The principal aim of the initiative is to reduce carbon emissions.
- The principal function of the liver is to detoxify the body and metabolize nutrients.
- The principal character in the story undergoes a significant transformation.
- Budgetary concerns are the principal obstacle to implementing the new program.
- The principal challenge in the negotiation process is reaching a mutually beneficial agreement.