chooser

One who picks

A chooser is someone who selects from available options.

The word appears most often in the expression beggars can't be choosers, meaning those in need shouldn't be picky about what's offered.

Outside this phrase, chooser is uncommon—picker or selector tend to sound more natural in most contexts.

sensename

selector

Mechanism for choosing

voter · nominator · appointer · designator · determiner · selectee · elective · selective

preference

discriminator

Thing that differentiates

critic · evaluator · assessor · appraiser · ranker · prioritizer · sorter · filterer

decider

arbitrator

One who resolves disputes

referee · umpire · mediator · resolver · settler · finalizer · tiebreaker

agency

free-will

Autonomous decision-making capacity

deliberation · intention · discretion · prerogative · liberty · independence · empowerment · sovereignty

Opposites
agency in selection

chooseraccepter

One who receives willingly

follower · taker · chosen · selectee · recipient

selector vs. selected

chooserchosen

Selected from alternatives

chosen one · selectee · selected · candidate · option

Phrases
Family

choose, choosing, choosy, chooses, choosers, choosey

Familiarity
Top 100,000
Profile
Known to kids · Used worldwide · Timeless · Everyday, not technical · Rated G