visual purple

noun

: a photosensitive red or purple pigment in the retinal rods of various vertebrates

especially : rhodopsin

Word History

First Known Use

1878, in the meaning defined above

Kids Definition

visual purple

noun

: a red or purple pigment in the retina of various vertebrates including human beings that is sensitive to dim light and functions in night vision

Medical Definition

visual purple

noun

: rhodopsin