missing link

noun

1

: an absent member needed to complete a series or resolve a problem

2

a

: a hypothetical intermediate evolutionary form between humans and their presumed simian progenitors

b

: a hypothetical intermediate evolutionary form between one animal species or group and its presumed ancestors

a missing link between reptiles and birds

Example Sentences

Police are hopeful that the new evidence will provide the missing links needed to solve the crime.

scientists searching for the missing link

Recent Examples on the Web

During their study of V883 Orionis, the researchers realized the missing link between the young stars born from clouds of gas and dust that include water molecules, and the comets also created from those same clouds swirling around newborn stars. —Ashley Strickland, CNN, 8 Mar. 2023

Then-Mayor Ed Murray brokered a deal between the Ballard Coalition and the Cascade Cycling Club that rerouted part of the missing link away from the waterfront. —Paul Roberts, Anchorage Daily News, 17 Feb. 2023

The missing link between your TV and true hands-free Alexa voice control is finally here and it’s called the Fire TV Blaster. —Maren Estrada, BGR, 30 Mar. 2021

Two years after Charles Darwin published On the Origin of Species, the discovery of a missing link between dinosaurs and birds gave evolutionary theory a fortuitous credibility boost. —Jonathon Keats, Discover Magazine, 21 June 2019

Therapies that repair damage are the missing link in treating MS. —Andrew Moseman, Discover Magazine, 6 Dec. 2010

Grace posed the question about the importance of the phones involved, and how the interactions on social media between the victims and Kohberger could be the missing link for a motive. —Agustin Hays, Fox News, 19 Jan. 2023

Dose plus host makes the poison — and host susceptibility is the missing link. —Jill Neimark, Discover Magazine, 10 Dec. 2013

Though its swimming days ended about 400 million years ago, this fossilized fella — with the great name of Doliodus problematicus — has found its place as a missing link in the deep backstory of some of today's most intriguing and iconic animals. —Gemma Tarlach, Discover Magazine, 15 Mar. 2017

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Word History

First Known Use

1851, in the meaning defined at sense 1

Kids Definition

missing link

noun

: a form of animal believed to have existed that shares characteristics with one animal group and the ancestors from which the group is thought to have evolved but has not been discovered in the fossil record

find the missing link between humans and apes