anus
noun
ˈā-nəs 
: the posterior opening of the digestive tract
Example Sentences
Recent Examples on the Web Human studies have found that baby boys who were exposed to higher phthalate levels during fetal development had shorter distances between their anuses and genitals — a measure linked to lower testosterone levels and semen quality later in life. 
New York Times, 17 Apr. 2020 Wombats have roundish anuses, just like the rest of us mammals. Jill Kiedaisch, Popular Mechanics, 20 Nov. 2018 Overall, then, evolution easily could have done a U-turn long ago and developed fancier folds around our anuses for rectal talking. Sam Kean, Slate Magazine, 24 July 2017 An estimated 80 million in the U.S. have HPV, which is usually cleared by the immune system but causes most cervical cancers and some cancers of the anus and throat. Todd Ackerman, Houston Chronicle, 28 Dec. 2017
New York Times, 17 Apr. 2020 Wombats have roundish anuses, just like the rest of us mammals. Jill Kiedaisch, Popular Mechanics, 20 Nov. 2018 Overall, then, evolution easily could have done a U-turn long ago and developed fancier folds around our anuses for rectal talking. Sam Kean, Slate Magazine, 24 July 2017 An estimated 80 million in the U.S. have HPV, which is usually cleared by the immune system but causes most cervical cancers and some cancers of the anus and throat. Todd Ackerman, Houston Chronicle, 28 Dec. 2017 Word History
Etymology
borrowed from Latin ānus "ring, anus," perhaps going back to an Indo-European base *h1eh2n-o-, whence also, with different suffixation, Old Irish áinne "ring," Armenian anur, genitive-dative anroy "ring, necklace, collar"
First Known Use
15th century, in the meaning defined above
Kids Definition
anus
noun
ˈā-nəs
: the lower opening of the digestive tract
Medical Definition
anus
noun
ˈā-nəs
plural anuses or ani ˈā-(ˌ)nī
: the posterior opening of the digestive tract