Scar·let, a. Of the color called scarlet; as, a scarlet cloth or thread.
 Scarlet admiral Zool., the red admiral. See under Red. -- Scarlet bean Bot., a kind of bean (Phaseolus multiflorus) having scarlet flowers; scarlet runner.
 Scarlet fever Med., a contagious febrile disease characterized by inflammation of the fauces and a scarlet rash, appearing usually on the second day, and ending in desquamation about the sixth or seventh day.
 Scarlet fish Zool., the telescope fish; -- so called from its red color. See under Telescope.
 Scarlet ibis Zool. See under Ibis.
 Scarlet maple Bot., the red maple. See Maple.
 Scarlet mite Zool., any one of numerous species of bright red carnivorous mites found among grass and moss, especially Thombidium holosericeum and allied species. The young are parasitic upon spiders and insects.
 Scarlet oak Bot., a species of oak (Quercus coccinea) of the United States; -- so called from the scarlet color of its leaves in autumn.
 Scarlet runner Bot., the scarlet bean.
 Scarlet tanager. Zool. See under Tanager.