IPA: /ˈmɑːrkər/
KK: /ˈmɑrkər/
An object used for writing or marking, often with ink, such as a pen or a felt-tip pen.
I used a marker to write my name on the poster.
Marker → The word 'marker' is derived from the verb 'mark' (from Old English 'mearcian', meaning to mark or designate) and the suffix '-er' (meaning a person or thing that performs an action). A marker is therefore something that marks or designates an area or object.
Think of something that 'marks' an area or object — that's what a 'marker' does, and the '-er' indicates it is the thing that performs the marking.