have been mainlining

• 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 mainline.
  mainline

  verb (used without object)

  to inject a narcotic, especially heroin, directly into a vein.

Related Words

• dominant
• key
• leading
• main
• major
• outstanding
• paramount
• predominant
• preeminent
• primary
• prime
• prominent