One who beribons or decorates with ribbons; someone who adorns things with ribbons.
Agent noun formed from 'beribbon' plus the '-er' suffix, indicating a person who performs the action of decorating with ribbons. This follows standard English patterns for creating occupational or action nouns.
The fact that there's actually a word 'beriber' shows how much Victorians valued ribbon decoration—you needed a term for the person whose job was literally to cover things in ribbons.
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