What does the expression "jump on the bandwagon" imply?

'Pass away' means: You should show good manners in the company of young ladies . What is the meaning of the phrase ‘At home with’? In black and white means / 'Black and white' means- Some interesting facts about your past have just come to light. Here 'come to light' means- Through thick and thin' means - Acid test - means 'Apple of one’s eye' means- Not many people can commit such a heinous crime in cold blood. What does the italicized idiom above mean ? “Fag end” means—