1. Characterized by hard work and perseverance
   - industrious, tireless, untiring

See also: diligent

• heating system
• heatless
• heatstroke
• heaume
• heave
• heave up
• heave-ho
• heaven
• heaven-sent
• heavenly
• heavenly body
• Heavenly City
• Heavenly Jewel
• heavens
• heavenward
• heavenwardly
• heavenwards
• heaver
• heaves
• heavier-than-air
• heavier-than-air craft
• heavily
• heavily traveled
• heavily travelled
• heaviness