halphorism 

A common saying or phrase of which the second half is usually omitted.

Most people don't realize, but "Curiosity killed the cat" is actually a misleading halphorism; it actually ends with "but satisfaction brought it back".

halphorism by markstheshark March 1, 2015

Halphorism 

an incomplete idiomatic expression stated by a person who expects the audience to know the rest of the saying.

"Emily just used a halphorism. 'These two things are the same. Ya know...like six of one half a dozen of the other.'"
"Richard is fond of using halphorisms, like, 'Nutrition is important for good health. As they say, an apple a day keeps the doctor away'."

Halphorism by trogers91 November 20, 2023