Wiktionary
magic marker
n. A felt-tipped pen.
Usage examples of "magic marker".
Someone has drawn a skull on it with a Magic Marker or grease pencil.
I check the pocket inside the waistband and pull out a steel key etched with Do Not Duplicate, and written on it in permanent Magic Marker is the number 233.
One of the stone sphinxes was lying on the floor, tipped on its side, defaced with Magic Marker—.
In green and purple crayon, outlined with black Magic Marker for emphasis, was a new company directive: EFFECTIVE IMMEDIATELY, ALL EMPLOYEES WILL BE REQUIRED TO TAKE A COMBINATION OF GINKGO AND VIAGRA, SO YOU CAN REMEMBER WHAT THE FUCK YOU'RE DOING.