A dock or small dock structure; or a type of plant (another name for dock, particularly sorrel), primarily Scottish/Northern English.
From Old English 'doc' or Scots variant, possibly related to 'dock' the plant. The diminutive suffix '-en' creates a smaller or more familiar version of the word, common in Scots dialects.
Docken is one of those wonderful regional words that shows how the same root ('dock') created completely different meanings—one for plants and one for maritime structures—and dialect kept the old plant-related version alive.
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