missing link

American  

[mis-ing lingk] / ˈmɪs ɪŋ ˈlɪŋk /

noun

1. a hypothetical form of animal assumed to have constituted a connecting link between the anthropoid apes and humans, identified by some authorities as constituting the genus Australopithecus.

2. something lacking for the completion of a series or sequence.

   It’s tricky to find the missing link between children’s books and adult fiction.

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missing link British  

noun

1. (sometimes capitals) a hypothetical extinct animal or animal group, formerly thought to be intermediate between the anthropoid apes and man

2. any missing section or part in an otherwise complete series

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missing link Cultural  

1. A supposed animal midway in evolution between apes and humans. The term is based on a misunderstanding about the theory of evolution, which does not state that humans are descended from apes, but rather maintains that both humans and apes descended from a common ancestor. Modern evolutionary scientists do not search for a “missing link.”

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Etymology

Origin of missing link

First recorded in 1850–55

Example Sentences

See Examples For:

missing link

But the long-awaited automated people mover — considered by some to be a crucial missing link in the region’s commuter rail network — has yet to transport a single passenger.

From Los Angeles Times ● Jun. 24, 2026

The Zambian segment of the Lobito Corridor -- often described as the missing link -- is not on LAR's near-term agenda, he added, citing the scale and cost of rehabilitating the rail infrastructure.

From Barron's ● May 7, 2026

The critical missing link at present is a viable transitional government.

From The Wall Street Journal ● Mar. 17, 2026

"I lost all my confidence after my diagnosis and treatment, so to bring the three of us together again to complete the missing link in our journey has been such a healing process," she said.

From BBC ● Nov. 14, 2025

He had found the missing link in Harvey’s description of blood circulation, a link which Harvey himself had guessed must be there, but could not detect with the instruments at his disposal.

From "The Scientists" by John Gribbin