molecula

plural moleculae

1. historicalA molecule; a small particle of something.First known use 18th c.

   Smal bodies, of Atoms, out of whose various combinations bigger molleculæ are made.

   1751, John Locke, Elements of Natural Philosophy, section XII

   1 more example

   They acted by the ancient organized states in the shape of their old organization, and not by the organic moleculae of a disbanded people.

   1790, Edmund Burke, Reflections on the Revolution in France, Oxford, published 2009