An archaic term for someone who practices or specializes in drying; possibly someone who dries goods or preserves food by removing moisture.
From 'dry' with the agent suffix '-ster' (one who does something), a common Middle English formation for creating occupational titles from verbs, though this particular word is now obsolete.
Before modern technology, drying food was a specialized skill—drysters would have been crucial to medieval food preservation, yet this job title has completely disappeared from English, replaced by words like 'dehydrator'.
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