D defs.my
Entry 1 sense Webster, 1913

Frost signal

· Frost· sig·nal · IPA
01 A signal consisting of a white flag with a black center, used by the United States Weather Bureau to indicate that a local frost is expecte…
  1. 1.
    A signal consisting of a white flag with a black center, used by the United States Weather Bureau to indicate that a local frost is expected. It is used only in Florida and along the coasts of the Pacific and the Gulf Mexico.(Meteor.)