foresail

/F AO1 R S EH0 L/
noun
  1. 1

    (on a square-rigged ship) The lowest (and usually the largest) square sail hung on the foremast

  2. 2

    A square fore-and-aft sail set on the foremast, but behind it, on a schooner or other similar vessel.

  3. 3

    (on a sloop) A triangular sail set forward of the foremast: forestaysail.

Source: https://en.wiktionary.org/wiki/foresail