Age before beauty. means older people first.
All system go! means everythings is OK/ready.
Be a million miles away. for example: Jim is always a million miles away when he is reading.
Be a religious about sth. means do sth. everyday/ a lot.
Beats me! means I don't know.
Been under the weather.means a little sick.
Bite your tongue! means don't say that!
Break a leg! means good luck.
By the skin of your skin. means only just succeed. For example: I passed the exam by the skin of my skin!
You can bank on it or you can take it to the bank. means you can trust / depend on it.
Can it! means shut up!
Ciao! [ tʃəu ] means goodbye for a short time(Italian).
Capice?/Capeesh? put it on the end of a sentence, means "understand?"