Wiktionary
a. moisten in advance.
Usage examples of "premoistened".
After tearing open a small packet containing a premoistened antiseptic pad, he thoroughly cleaned the cut and the area around it, pretending not to notice her involuntary flinches of pain, which she quickly tried to control.
Fortunately he'd been premoistened and she found herself rapidly lubricating the area.
She took one of those premoistened towelettes from her purse, ripped off the foil, wiped down the mouthpiece.
This does not even take into account the occasional use of bathroom tissue for unpredictable/creative purposes such as applying/removing cosmetics, beverage-spill management, etc For this reason, rather than trying to package bathroom tissue in small one-transaction packets (as is done with premoistened towelettes, for example), which can be wasteful in some cases and limiting in other cases, it has been traditional to package this product in bulk distribution units whose size exceeds the maximum amount of squares that an individual could conceivably use in a single transaction (barring force majeure).