have been staining

• present perfect progressive

  present perfect progressive

  Used to describe an action that began in the past, has continued continuously, and is still in progress.

  of stain.
  stain

  noun

  a discoloration produced by foreign matter having penetrated into or chemically reacted with a material; a spot not easily removed.

Related Words

• besmirch
• blacken
• contaminate
• daub
• discolor
• dye
• smear
• smudge
• sully
• tar
• tarnish
• tint