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?
Best Answer
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