Plural of 'gullery': instances of deceptive tricks or fraudulent schemes.
From 'gullery' (trickery), formed from 'gull' plus the suffix '-ery' (practices or instances of something). The plural '-ies' is standard for nouns ending in '-y'.
The '-ery' suffix has a medieval flavor—it gave us 'archery,' 'witchery,' 'snobbery'—and they all suggest habitual or characteristic behavior, not just single acts.
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