C15 hach-boon, altered from earlier nache-bone, nage-bone (a nache mistaken for an ache, an aitch; compare adder1); nache buttock, via Old French from Late Latin natica, from Latin natis buttock
aitchbone in American English
(ˈeɪtʃˌboʊn)
noun
1.
the rump bone
2.
a cut of beef around the rump bone
Word origin
by faulty separation of ME a nache bone < OFr nache, buttock < VL *natica, dim. < L natis, buttock