Genoa
From MITNA
A genoa, or "genny", is a large foresail on a sloop or other sailboat, much like a jib sail, but larger.
Jibs and genoas are often described by their size relative to a boat's foretriangle. The foretriangle is the triangle created by the mast, the forestay, and the deck between the mast and the bow. If a jibsail's area is 80% of the area of the foretriangle, it is referred to as an "80% jib". Generally, if the sail's area is greater than 100% of the foretriangle, it is referred to as a genoa, not a jib, but the terms are often interchanged.
Genoas as large as 150% are common on ocean-going sailboats.