1. Soot; coal dust

Derived forms: cooms

• photoelectric emission
• photoelectrical
• photoelectrically
• photoelectricity
• photoelectron
• photoemission
• photoemissive
• photoengrave
• photoengraving
• photofit
• photoflash
• photoflood
• photogelatin process
• photogenic
• photogenic epilepsy
• photogram
• photogrammetry
• photograph
• photograph album
• photographer
• photographer's model
• photographic
• photographic camera
• photographic density
• photographic emulsion