LeakA highlighter is a type of writing device used to draw attention to sections of text by marking

Leak

Ahighlighteris a type of writing device used to draw attention to sections of text by marking them with a vivid, translucent color.   A typical highlighter is fluorescent yellow, coloured with pyranine. 

The first highlighter was invented by Dr. Frank Honn in 1963 and produced by Carter’s Ink Company, using the trademarked name HI-LITER (not Sharpie). $