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

See also: incautious

• Sciurus hudsonicus
• Sciurus niger
• Sciurus vulgaris
• sclaff
• sclera
• scleral veins
• Scleranthus
• Scleranthus annuus
• scleredema
• sclerenchyma
• sclerite
• scleritis
• scleroderma
• Scleroderma aurantium
• Scleroderma bovista
• Scleroderma citrinum
• Scleroderma flavidium
• Sclerodermataceae
• Sclerodermatales
• sclerometer
• Scleropages
• Scleropages jardinii
• Scleropages leichardti
• Scleroparei
• scleroprotein