Make no bones about it is fairly literal. It hails back to the days of broth based soups that had no bones in them. No bones in the meal ensured that you were able to swallow without difficulty or objection. ( source ) Today when we utter the phrase what we are saying is that no matter how awkward or unpleasant something is we are still going to speak clearly about it.

Due to the number zero looking *like* an egg this saying started popping up when scoreboards would publish zeros as scores for teams who didn't do well. People started saying the team, or player, had laid an egg. You could use the term for just about anything that gets a score of zero - a sport, a grade, etc.  There's a couple of different sources for this term, to read up on them click here and here .

Keep your chin up has a rather obscure history. Read about its origins here . 

Nothing good comes from boredom. Here's some thoughts on the origins of this phrase.

Clams are happy at high tide because they can't be harvested then. They can only be harvested during low tide. High tide also keeps other dangers away from the clams so if they had emotions they would be feeling happiness. ( source ) Figuratively the phrase means that someone is happy because nothing awful or negative can touch them at that moment. 

The term scot free has a couple of different theories, click here to read about them. The most plausible seems to be when you can get off of paying taxes. 

The origin of this phrase is an aggressive attack on prey by sharks (yes I know the above picture is not of sharks *grin*) that can result on them turning even on each other. ( source ) Looting and rioting always makes me think of the phrase feeding frenzy due to the actions that are taken against each other, We are our own and yet we turn on each other for such ridiculous reasons. 

This saying literally has its origins in Elvis. When his show would end the announcer would say, "Ladies and gentlemen, Elvis has left the building. Thank you and goodnight." So it's become a phrase for saying the show is over, go home.  ( source ) Elvis has left the building Artist: Thistle Chan

A ringer is a horse substituted for another of similar appearance in order to defraud the bookies. This word originated in the US horse-racing fraternity at the end of the 19th century. The word is defined for us in a copy of the Manitoba Free Press from October 1882: "A horse that is taken through the country and trotted under a false name and pedigree is called a 'ringer.'" And the addition of "dead" for the phrase, in this case, means "exact." Spot on mate.   Source So its meaning then, and now, is an exact duplicate. Like looking in the mirror. 

This phrase traces back to author Anthony Trollope and his book  The Kellys and the O'Kellys , published in 1848. The line, slightly different than the phrase as we know it now, read this way:  “If it was to save my life and theirs, I can’t get up small talk for the rector and his curate.” It means that if my very life depended on completing a task or something then I would most likely die.

The figurative and derogatory meaning of 'back-seat driver' is unambiguous in this from The Bismarck Tribune a few years later - December 1921: "A back-seat driver is the pest who sits on the rear cushions of a motor car and tells the driver what to do. He issues a lot of instructions, gives a lot of advice, offers no end of criticism. And doesn't do a bit of work." ( source ) Today it means someone (or something) basically doing the same thing but in more figurative terms.

"It's said that in the year 1796, the first U.S. dimes were produced for circulation. Hence, it would make sense for this phrase to originate sometime after." Read more here .  Today the phrase carries the meaning that something is cheap or without value if it can be lumped in with other similar or exactly-like things. It's more of an insult than anything.

I have NEVER heard this one!  Fascinating. It's rarely, if ever, used anymore. But here and here gives a great history of the slang. 

Anthelme Brillat-Savarin wrote, in Physiologie du Gout, ou Meditations de Gastronomie Transcendante, 1826: "Dis-moi ce que tu manges, je te dirai ce que tu es." [Tell me what you eat and I will tell you what you are]. In an essay titled Concerning Spiritualism and Materialism, 1863/4, Ludwig Andreas Feuerbach wrote: "Der Mensch ist, was er ißt." That translates into English as 'man is what he eats'. For an in-depth explanation of the origin and evolution of the term click here .

The term 'wag the dog' comes from the expression that a dog is smarter than its tail, but if the tail were smarter than the dog, the tail would be in control. ( source )

Variety's the very spice of life, That gives it all its flavour. "The Timepiece", The Task, II, 1785, lines 606–7 Penned by William Cowper (above) this phrase has stayed true to its original meaning for the most part. 

The meaning of this phrase has changed from its origin. It originally meant to take cover under the weather deck on a ship. Unfortunately taking cover under the weather deck was never a positive, it was called the weather deck for a reason - it's where all the weather hits or collects! As years passed the phrase morphed into what we know it to mean these days, to feel ill or depressed. I can see how it turned into that from the weather deck through someone getting ill from being "under the weather deck."  For more on this phrase starting off as one thing and becoming a different thing click here .