A rare or obsolete term, possibly for someone who makes or tailors breeches, or someone concerned with that body part.
From 'buttock' with the agent suffix '-er,' a word-formation pattern that creates nouns for people who perform actions, though this particular word never entered common usage.
This word is so obscure that most English dictionaries don't even include it—it's a fossil of Medieval English tailoring terminology, preserved only in the oldest unabridged references.
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