1. Marked by excessive enthusiasm for and intense devotion to a cause or idea
   - fanatic, fanatical, rabid

See also: passionate

• approbative
• approbatory
• appropriable
• appropriate
• appropriately
• appropriateness
• appropriation
• appropriation bill
• appropriative
• appropriator
• approval
• approve
• approved
• approver
• approving
• approvingly
• approx
• approximate
• approximate range
• approximately
• approximation
• approximative
• appurtenance
• appurtenant
• APR