missing link
noun /ˌmɪsɪŋ ˈlɪŋk/
/ˌmɪsɪŋ ˈlɪŋk/
- [countable] something, such as a piece of information, that is necessary for somebody to be able to understand a problem or in order to make something complete
- He may be able to provide us with the missing link that can help us solve the mystery.
- the missing link[singular] an animal similar to humans that was once thought to exist at the time that apes were developing into humans