fouling
污底; 汙垢
Foul v. t. [imp. & p. p. Fouled p. pr. & vb. n. Fouling.]
1. To make filthy; to defile; to daub; to dirty; to soil; as, to foul the face or hands with mire.
2. Mil. To incrust (the bore of a gun) with burnt powder in the process of firing.
3. To cover (a ship's bottom) with anything that impered its sailing; as, a bottom fouled with barnacles.
4. To entangle, so as to impede motion; as, to foul a rope or cable in paying it out; to come into collision with; as, one boat fouled the other in a race.