Likely to become successful or popular soon. You use it for someone or something on the way up but not there yet: "an up-and-coming young director," "an up-and-coming band," "an up-and-coming neighbourhood." Two halves of the meaning sit inside it. There is talent or promise now, and there is a prediction about later. That prediction is doing real work — the phrase says "watch this one." So it is warm and positive, the kind of thing a reviewer or a magazine says about a person they admire. But notice the quiet edge: calling someone up-and-coming also says they have not arrived yet. An already-famous actor would not be pleased to be called up-and-coming. It fits the young, the new, the rising. Beyond people it is very common for places — an up-and-coming area is one where new cafés and shops are opening and prices are rising. Estate agents love the phrase for exactly that reason. Form: it is a compound adjective and normally keeps both hyphens, sitting before a noun. "She's up and coming" without the noun is heard but is less usual; "a rising star" or "on the rise" are the everyday alternatives. Register: neutral, slightly journalistic. Common in news, reviews, and business talk.