IPA: /ˈtʃuːzər/
KK: /ˈtʃuzər/
A person who selects or makes a choice from a group of options.
As a chooser, she carefully considered all her options before making a decision.
Chooser → It is formed from "choose" (from Old English "ceosan", meaning to select or pick) and "-er" (meaning a person who). The word "chooser" refers to a person who selects or makes a choice.
Think of someone who 'selects' ('choose') something — the '-er' indicates that this person is the one making the choice.