A person who chortles; someone who laughs in a joyful, chuckling way.
From 'chortle' (to laugh joyfully) + '-er' (one who performs the action). This is a standard English agent noun formation applied to Carroll's invented verb.
A chortler is rare in literature and life—they're someone whose laughter is so genuine and uncontrolled that they literally can't help but make that distinctive chortling sound, which might be why we love characters who chortle in stories.
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