MAINLINE is a playable word

mainline Scrabble® Dictionary

verb
mainlined, mainlining, mainlines
to inject a narcotic into a major vein
103 Playable Words can be made from "MAINLINE"
   2-Letter Words (16 found)
   3-Letter Words (24 found)
   6-Letter Words (4 found)
   7-Letter Words (4 found)
   8-Letter Words (1 found)