General:
* Contaminate: This is a broad term that means to make something impure or harmful by adding something undesirable. Example: "The water was contaminated by the chemical spill."
* Adulterate: This refers to making something impure by adding inferior or harmful substances. Example: "The milk was adulterated with water."
* Defile: This implies a moral or spiritual impurity, often through contact with something considered unclean or taboo. Example: "The sacred ground was defiled by the enemy's presence."
* Pollute: This is often used for environmental contamination, meaning to make something harmful or unfit for use by adding harmful substances. Example: "The air was polluted by factory emissions."
Specific:
* Tarnish: This specifically refers to the dulling or discoloration of a metal surface due to oxidation or other chemical reactions. Example: "The silver tarnished after being exposed to air."
* Corrupt: This refers to making something morally impure or dishonest by adding something corrupting. Example: "Power can corrupt even the best of intentions."
Choosing the right word:
* Consider the nature of the impurity: Is it physical, chemical, biological, moral, or spiritual?
* Think about the context: What is being contaminated or polluted?
* Pay attention to the severity of the impurity: Is it a minor blemish or a major threat?
By considering these factors, you can choose the word that best describes the specific situation.