vibratiuncle

noun1

1. •
   (historical) A minuscule or slight vibration; specifically, a vibration in brain tissue caused by the comparatively greater vibrations of the particles of the medullary substance of the nerves (formerly hypothesised to convey external impressions to the mind).

   • Diminutive Vibrations, which may also be called Vibratiuncles and Miniatures. — 1749