1. (physics) a measure of the extent to which a substance transmits light or other electromagnetic radiation
   - optical density, transmission density, absorbance

Type of: denseness, density

• heathlike
• heathy
• heating
• heating element
• heating oil
• heating pad
• heating plant
• 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