some conspicuous object used to distinguish or mark something
"the buoys were markers for the channel"
a writing implement for making a mark
"The teacher used a dry-erase marker to circle the correct answer on the board."
An object used to mark a location.
"The hiker placed a bright orange marker on the trail to indicate where she had rested."
In plain English: A marker is an object used to mark something so it stands out from its surroundings.
"She used an orange marker to circle her favorite item on the grocery list."
Usage: As a noun, the most common everyday meaning of marker is an ink pen with felt tips rather than its role as a person who marks scores in sports. Use this word for writing instruments or temporary signs that indicate specific locations on surfaces like paper or floors.
To mark or write on (something) using a marker
"She used her favorite blue marker to highlight important notes in the textbook."
In plain English: To mark something means to put your name on it so you know who owns it.
"She marked her spot in the book with a bright yellow highlighter so she could find it again later."
The word marker is formed by adding the suffix -er to mark, indicating a person or thing that makes a mark. It entered English as a straightforward compound of these two elements without any shift in meaning from its original components.