monotreme

noun

mono·​treme ˈmä-nə-ˌtrēm 

: any of an order (Monotremata) of egg-laying mammals comprising the platypuses and echidnas

Examples of monotreme in a Sentence

Recent Examples on the Web

Also known as spiny anteaters, these iconic monotremes are native to Australia and New Guinea. —Melissa Cristina Marquez, Forbes, 28 Sep. 2024

Their mammary glands are markedly different from those of eutherian mammals such as cows and humans that have nipples; monotremes instead secrete milk through specialized mammary hairs. —Gat Rauner, The Conversation, 13 Aug. 2024

And both echidnas and platypuses are considered monotremes. —Paul Smaglik, Discover Magazine, 29 May 2024

Why did those teeth end up disappearing altogether in modern monotremes? —Elizabeth Rayne, Ars Technica, 7 June 2024

Word History

Etymology

borrowed from French monotrème, from mono- mono- + -trème, borrowed from Greek trēmat-, trêma "aperture, hole"; so named because members of the order have a single orifice for both excretory and reproductive functions — more at trematode

Note: The name was introduced by the French naturalist Étienne Geoffroy Saint-Hilaire (1772-1874) in "Extrait des observations anatomiques de M. Home, sur l'echidné," Bulletin des sciences, par la Société Philomathique, no. 77 (Thermidor, An 11 [July, 1803]), pp. 225-26. The word was subsequently latinized as a plural taxon Monotremata.

First Known Use

1835, in the meaning defined above

Kids Definition

monotreme

noun

mono·​treme ˈmän-ə-ˌtrēm 

: any of an order of egg-laying mammals that include the platypuses and echidnas

Medical Definition

monotreme

noun

mono·​treme ˈmän-ə-ˌtrēm 

: any mammal (as a platypus) of the order Monotremata