Promising means showing signs of turning out well. A promising start, a promising young player, look promising.
It is praise with a condition attached — a promising player has not done it yet, and promising is faintly damning when said of somebody who has had time. It is the standard word in reports for early results that are not yet proof.
1adjectivepromisingShowing signs of turning out well.
“She's a promising young pianist who has already won several competitions.”
promising is a quality.