From Late Latin acnestis, from Koine Greek ἄκνηστις (áknēstis, “spine”), from κνῆστις (knêstis, “spine, cheese-grater”), or from ἀ- (a-) + -κναίειν (-knaíein, “grate, scrape, scratch”) (only attested in compounds), or from incorrect segmentation of κατὰ κνῆστιν (katà knêstin, “on the spine”) (see Homer, Odyssey 10.161), ultimately from Proto-Indo-European *kneh₂-.
- (zoology) The section of an animal's skin that it cannot reach in order to scratch itself, usually the space between the shoulder blades.
- 1794, John Quincy, Lexicon Physico-medicum: Or, a New Medicinal Dictionary. Explaining the Difficult Terms Used in the Several Branches of the Profession. And in such Parts of Natural Philosophy, as are Introductory thereto. With an Account of the Things Signified by such Terms. Collected from the most Eminent Authors, 11th edition, London: Printed for T[homas] Longman, in Pater-noster Row, OCLC 83408483, pages 16–17:
- Acneſtis, from α priv. and κναειν to ſcratch. That part of the ſpine of the back, which reaches from the metaphrenon, which is the part betwixt the ſhoulder blades, to the loins. This part ſeems to have been originally called ſo in quadrupeds only, becauſe they cannot reach it to ſcratch.
- 1802, W[illiam] Turton, A Medical Glossary: In which the Words in the Various Branches of Medicine are Deduced from their Original Languages; Properly Accented and Explained, 2nd edition, London: Printed by J. D. Dewick, Aldersgate Street, for Lackington, Allen, and Co. Temple of the Muses, Finsbury Square, OCLC 458430143, page 11:
- ACNÉSTIS (ακνηςις, from α neg. and κναω to ſcratch). That part of the ſpine between the ſhoulder-blades, and which extends to the loins. It is ſo called from the difficulty there is to reach and ſcratch it.
- 1927 April 3, The Observer, London:
- That spot known to crossword solvers as the acnestis.
- 2000, Otto Braun-Falco; Gerd Plewig; Helmut H. Woolf; Walter H. C. Burgdorf, Dermatology, 2nd completely rev. edition, Berlin: Springer-Verlag, →ISBN, page 991:
- Excoriations are typically linear and occur where the patient can reach with his hands. […] The middle of the back is typically spared, although with a back scratcher, this rule loses value. This pattern of sparing has been called the reverse butterfly sign; the Greek word for the area that cannot be reached is acnestis.
- 2008 August 5, New Straits Times, Kuala Lumpur, Malaysia:
- In what has to be the longest post-election season in living memory, the last five months have felt like an acnestis upon our collective soul; like that little patch of skin on our backs that we just can't reach to scratch ourselves. It's irritating. It's annoying. It's left us reaching and spinning around in circles.
- 2010, Blaize Clement, Raining Cat Sitters and Dogs: A Dixie Hemingway Mystery, New York, N.Y.: Thomas Dunne Books, →ISBN, page 24:
- I nudged Winston [a cat] to one side of his chair and sat down beside him. I scratched the spot between his shoulders, the acnestis that animals can't scratch by themselves, and he looked up at me and smiled.
- 2010, Ammon Shea, Satisdiction: One Man's Journey into all the Words He'll Ever Need, London: Penguin Books, →ISBN:
- Acnestis (n.) On an animal, the point of the back that lies between the shoulders and the lower back, which cannot be reached to be scratched. I am very glad I found this word early in my reading of the OED – the fact that there existed a word for this thing which previously I had been sure lacked a name was such a delight to me that suddenly the whole idea of reading the dictionary seemed utterly reasonable.
For more quotations using this term, see Citations:acnestis.