clavis

Etymology

From Latin clāvis (“a key”). Doublet of clef.

noun

1. (archaeology) A Roman key.
   Iron clavis, the solid web-shaped at the edges to fit the wards in the lock, and having a pointed broach and a kite-formed looped haft. 1873, “Proceedings of the Association”, in Journal of the British Archaeological Association, volume 29, April 9th, page 202
2. A device for restraint of the hands.
   His hands were restrained by means of a clavis and bolt (of iron), appropriated to each wrist, and united by a padlock. 1904, B. O. Flower, “Editorials”, in B. O. Flower, editor, The Arena, volume 32, VI. Dr. Bell shows how hopeless insanity was a fruit of public parsimony, page 540, column 2
3. A glossary.
   Homer, with a clavis, I have had possession of some years. 12 July 1784, William Cowper, “To the Rev. William Unwin.”, in Robert Southey, editor, The Works of William Cowper, with a Life of the Author, volume 5, published 1836, page 54
4. (taxonomy) A key; an identification guide; a series of logically organized groups of discriminating information which aims to allow the user to correctly identify a taxon.
   There are many disadvantages in using a clavis intended for another country, which necessarily includes plants that are absent from our islands while it omits some that are present and neglects the peculiarities of our island flora. 1921, Alexander Irvine, “Short Notes: Rosa spinosissima×rubiginosa×f. cantiana, forma nova”, in Journal of Botany, British and Foreign, volume 59, number 702, page 180