A person who adds explanatory notes or comments to a text, document, or other material; an annotator.
From 'annotate' (Latin 'annotare' meaning 'to write upon') plus the agent suffix '-er' meaning 'one who does.' This variant spelling is less common than 'annotator' but appears in older English texts and some technical contexts.
Before Wikipedia editors, there were annotaters—scholars like Samuel Johnson who hand-wrote explanatory notes in margins for years, creating the first comprehensive 'databases' of knowledge by physically annotating entire libraries.
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