I'm a bit of a logophile. I also love idioms, proverbs, the like.
Happy as a clam- The original phrase was 'as happy as a clam at high water' which is when predators are the most infrequent (therefore the clams would be happy! :D) and was later abbreviated to just 'happy as a clam'.
Jaywalking (one that occurred to me randomly)-is apparently derived from a Kansas City term, jay, which means 'boldness'.
It ain't over 'till the fat lady sings-Though there is much dispute over the grammar in this idiom (many people say 'til, or isn't instead of ain't) the origin of the 'fat lady' came from Brunnhilde, a very tedious opera that was oftentimes concluded by a solo from a fat lady.
Dude-It originally meant a "fastidious man" and was New York slang. It was later utilized by Easterners to describe their findings in the west (i.e., dude ranches)
Hello-The most likely origin of this word seems to be the German words 'hala' or 'hola' and skyrocketed in popularity when it was more favored as a telephone greeting than Alexander Graham Bell's suggestion, ahoy.
Zig-zag-This is probably from the French word zigzag, which was used in the 1670's, or, possibly, from the German word zickzack. This word was originally used in the German military to depict siege approaches, and in English to describe garden paths.
Tabby-This word was first used in the 1630's, and was gleaned from the French word 'tabis', meaning a rich, watered silk that was usually striped. This term was later applied to cats, can be used as a nickname for Tabitha, or even slang for a "difficult old woman" in the 18th century.
Suggestions, comments, or concerns? Let me know!
http://www.phrases.org.uk/meanings/ October 22, 2013.
http://www.etymonline.com/Douglas Harper, 2013. October 22, 2013.