Smear campaign

Drop everything. The word literally is a metaphor. In the book I Is an Other by James Geary, we learn that actually, half or more of the words we use started life as metaphors.
See, literally comes from litera, Latin for letter. As in too the letter. The word litera, in turn, comes from the Latin linire, which means to smear. This comes all the way from when writers began to "smear" ink on parchment instead of carving them into wood or stone. 
Linera, by the way, is related to liniment, which you smear on your body. 

The salesman assured me that this was
"probably still good."
Sir, I have chewed the gum out of a 30-year-old
pack of trading cards, and you could not pay me
to open this bottle.