Question

what does the suffix -ist mean in the word optimist?
among the three sisters, the optimist had the brightest outlook.
one who shows a trait or ability
one who does or believes something
one who fights conviction or principle
one who has imagination or inner vision

Explanation:

The context sentence defines an optimist as someone with a bright outlook, meaning they hold a positive belief about outcomes. The suffix -ist here refers to a person who holds a specific belief or practice related to the root word "optim-". Comparing this to the options, the correct match is the definition of a person who does or believes something.

Answer:

one who does or believes something