Merriam-Webster Collegiate Dictionary - scarlet

 I. noun  Etymology: Middle English scarlat, ~, from Anglo-French e~, from Medieval Latin scarlata, from Persian saqalat, a kind of rich cloth  Date: 13th century  1. ~ cloth or clothes  2. any of various bright reds  II. adjective  Date: 14th century  1. of the color ~  2.  a. grossly and glaringly offensive sinning in flagrant and ~ fashion — G. W. Johnson  b. from the use of the word in Isaiah 1:18 & Revelation 17:1-6(Authorized Version) of, characterized by, or associated with sexual immorality a ~ woman