naproxen UK /nəˈpɹɒksən/US /nəˈpɹɑksən/ noun1 •A certain non-steroidal anti-inflammatory drug that inhibits the COX-1 and COX-2 enzymes and thereby reduces pain, fever, inflammation, and stiffness.These days, especially when she kept on top of taking her naproxen, the hurt in her joints and limbs merely teased. — 2021