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

Examples of missing link in a Sentence

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

The missing link: an understanding of and commitment to relevance. —Rachel Kule, Forbes.com, 21 July 2025

The missing link to understanding the H isotope systematics of the Moon. —Keith Cooper, Space.com, 16 July 2025

The find could therefore provide a missing link in the story of the evolution of molecules around young stars, accounting for the period between the initial formation of stars and the growth of planets in their surrounding protoplanetary disks. —Robert Lea, Space.com, 31 July 2025

Matching your workout to your personality type could be the missing link to making exercise feel less like a task and more like a reward. —Lauryn Higgins, Time, 16 July 2025

Word History

First Known Use

1851, in the meaning defined at sense 1

Rhymes for missing link

• bobolink
• countersink
• bethink
• downlink
• groupthink
• hoodwink
• rethink
• uplink
• blink
• brink
• chink
• cinque

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