Origin: Greek suffix -ist
Guitarist has 2 different meanings across 1 category:
a musician who plays the guitar
"The talented guitarist strummed his instrument during the final chorus of the song."
Someone who plays a guitar.
"The talented guitarist performed an energetic solo that captivated the entire audience."
In plain English: A guitarist is someone who plays music by strumming or plucking strings on a guitar.
"The talented guitarist performed her favorite songs at the local music festival last night."
The word guitarist is formed by adding the suffix -ist to guitar. It was first used as a compound term to describe someone who plays this specific stringed instrument.