Crossword Clue:

Hard to erase stuff

AnswerCrossword Clue
INKHard-to-erase stuff
BOOZEHard stuff to swallow
LACTOSEStuff some find hard to digest
TATTOOINKStuff that's hard to get off your chest?
WIPEErase, as a hard drive
VIRUSIt might erase your hard drive