›If you say that you would like to be a fly on the wall on an occasion, you mean that you would like to hear what will be said or see what will happen while not being noticed: I'd love to be a fly on the wall when those two get home!
New words are entering the language all the time. A few of these are completely new and original coinages, but the vast majority are based on the existing stock of words in some way, for example by using affixes (prefixes and suffixes). These can have the effect of changing the meaning of the
predicting the optimum date to buy a plane ticket, especially on a website or using an app A handful of new and updated websites and apps are trying to perfect the art of what’s known as farecasting – predicting the best date to buy a ticket.