Past tense of 'fid'—to use a wooden or metal tool called a fid, especially in sailing to separate rope strands or manage rigging.
From Dutch 'vijdt' or related nautical terminology. 'Fid' as a noun appears in maritime English by the 1600s, describing the tool used by sailors to handle thick ropes.
Sailors developed hyper-specific tools and verbs for their craft—'fidding' was so common on ships that it became its own verb, showing how specialized work creates specialized language.
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