Orig: a primitive root; to trample; hence, to wash (properly, by stamping with the feet), whether literal (including the fulling process) or figurative:--fuller, wash(-ing).
1) to wash (by treading), be washed, perform the work of a fuller 1a) (Qal) washer, fuller, treader (participle) 1b) (Piel) to wash (garments, person) 1c) (Pual) to be washed 1d) (Hothpael) to be washed out