A person or thing that cumbers; something that burdens, obstructs, or makes progress difficult.
From 'cumber' + '-er' (agent noun suffix), meaning 'one who cumbers' or 'that which cumbers'. Standard English word formation for creating agent nouns.
A 'cumberer' is anything from a person who slow-walks in front of you on the sidewalk to a extra heavy suitcase—it's a wonderfully old word for 'obstacle.'
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