What is the word for two-part phrases where the second (or first) half drops off?

Question

I remember some time ago learning a word for phrases where, over time, people forget the second (or first) half. So for example, the phrase "When in Rome, do as the Romans do" is often shortened to "When in Rome" — which makes no sense by itself, but the meaning of the phrase is still understood. While "do as the Romans do" is still fairly widely known, many of the examples provided were ones where the full phrase is not actually known — only the root of the phrase remains, keeping its original meaning from context.

Does anyone know what the term for this is?

Answer 1

This phenomenon is generally called an "ellipsis". But this word can also be used to describe a typographical sequence of three dots ("..."), often used to indicate missing speech rather than describe an incomplete saying.

If you want to be more precise (and technical) and avoid confusion, you can use the word "anapodoton".

UPDATE

Thought you might like some more examples: http://en.wiktionary.org/wiki/Appendix:English_examples_of_anapodoton

Answer 2

"Abbreviate" DOES mean to shorten in part, but I think what you are trying to find, specifically, is the word for a historic trend to abbreviate certain phrases, which has a history dating as far back as ancient Roman scripts. http://en.wikipedia.org/wiki/Abbreviation#History

Ironically, because it is so prolific in our language, there doesn't seem to be any word at all to describe this historic tendency. The best I can come up with would be just calling it "abbreviation" or, as suggested above, "phrase abbreviation".

If, however, you mean the 'forgetting' of the second part (or omitted part) of the phrase, while the meaning remains...I'm afraid I can't help you there. But you could perhaps emphasize that as what you're trying to find.

Answer 3

A 'short form' of a 'clipped form' or a 'phrase abbreviation'