pre·soak 
(prē-sōk)
(prē-sōk)tr.v. pre·soaked, pre·soak·ing, pre·soaks
To soak (laundry) before washing.
n. (prēsōk′)
1. The act or an instance of presoaking.
2. A liquid preparation in which laundry is presoaked.
3. A cycle on an automatic washing machine for presoaking laundry.