(~s, ~ing, ~ed)
Note: in AM, use 'discolor'
If something ~s or if it is ~ed by something else, its original colour changes, so that it looks unattractive.
A tooth which has been hit hard may ~...
Some oil had seeped out, ~ing the grass.
VERB: V, V n
~ed
Some of the prints were badly ~ed.
ADJ
discoloration
...the discoloration of the soil from acid spills.
N-UNCOUNT