We can conjure up the image of the injection of drugs into one's forearms for an invigorating effect, hence the use of this phrase often by politicians when they roll out economic measures to boost the economy. Therefore, something which is considered "a shot in the arm" is a form of short-term stimulus to drive up the intensity of something or lift someone's spirits. Example: Despite the defeat, the coach's encouraging words was definitely a shot in the arm and the players were determined to make a comeback. / The Japanese economy is set to get S$361 billion shot in the arm. (Reference: http://www.straitstimes.com/business/japanese-economy-to-get-361b-shot-in-the-arm) Hope this helps. Lance

I don't think I have ever used the phrase but I have seen it used from time to time by politicians and journalists in speech and in writing.

Thank you for your perfect explanation Sarah.

"Age before beauty", refers to letting the older person go before the younger. It is very informal, and more likely to be used in a joking manner. For example, two people close in age might be entering a room and the younger might say, "age before beauty." In this context, it is a form of mild teasing

And do you know or use ' Age Before Beauty'?