Enter a clue or pattern or both:
The Clue
Unit of light (4 letter answer)
The Answer
PHOT
Tags
Notes
The answer PHOT is rarely seen, appearing only about once every 1200 puzzles.
Related Clues
Light unit
Unit of illumination
Definition
PHOT as a noun:
1. a unit of illumination equal to 1 lumen per square centimeter; 10,000 phots equal 1 lux