Having no special skill or ability at something — no gift for it. It is a strong, quite unkind word. If you say a singer is talentless, you are not saying "she needs more practice"; you are saying there is nothing there to build on. That is why it appears so often in reviews, in comments under videos, and in arguments about famous people. People rarely use it about someone standing in front of them. Notice it is usually about a public performance kind of skill — singing, acting, writing, playing football — rather than about being good at, say, washing dishes. A softer, very common use is about yourself: "I'm completely talentless at drawing." Said about yourself it is a joke, or modesty, and nobody takes it seriously. Said about someone else it is an insult. Writers often push it further with a word in front — "utterly talentless", "a talentless hack" — which tells you the word already lives in angry, opinionated writing.