The act of sailing close to the wind WordNet 3.0 & Open English WordNet

In sailing, luffing refers to when a sailing vessel is steered far enough toward the direction of the wind, or the sheet controlling a sail is eased so far past optimal trim, that airflow over the surfaces of the sail is disrupted and the sail begins to "flap" or "luff". Wikipedia

nautical term Wikidata

The act of sailing a ship close to the wind. Wiktionary