Synonyms: foul, pollute, contaminate
Definition: make impure
Usage: The industrial wastes polluted the lake
Similar words: soil, grime, begrime, bemire, colly, dirty
Definition: make soiled, filthy, or dirty
Usage: don't soil your clothes when you play outside!
Synonyms: contaminate
Definition: make radioactive by adding radioactive material
Usage: Don't drink the water--it's contaminated
Similar words: alter, change, modify
Definition: cause to change; make different; cause a transformation
Usage: The advent of the automobile may have altered the growth pattern of the city; The discussion has changed my thinking about the issue