1. Characterized by undue haste and lack of thought or deliberation
   - hotheaded, impulsive, impetuous, madcap, tearaway

See also: incautious

• Merton
• Meryl Streep
• Meryta
• Meryta sinclairii
• mesa
• Mesa Verde National Park
• Mesabi Range
• Mesantoin
• Mesasamkranti
• mescal
• mescal bean
• mescal button
• mescaline
• mesclun
• Mesembryanthemum
• Mesembryanthemum crystallinum
• Mesembryanthemum edule
• mesencephalon
• mesenchyme
• mesenteric
• mesenteric artery
• mesenteric plexus
• mesenteric vein
• mesenteron
• mesentery