Plural of accessary; additional items that go with something more important, or persons who help in committing a crime.
From accessary, which comes from Medieval Latin accessarius. The plural adds -es following English rules (accessory/accessories being the more modern spelling).
The fascinating part is that 'accessaries' has two completely different meanings: fashion items (like belts with your outfit) and legal accomplices—the word 'accomplice' comes from the same Latin root for 'accompanying'!
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