con·tam·i·nate 
/kənˈtæməˌneɪt/ verb
con·tam·i·nates; con·tam·i·nat·ed; con·tam·i·nat·ing /kənˈtæməˌneɪt/ verb [+ obj] : to make (something) dangerous, dirty, or impure by adding something harmful or undesirable to it
▪ The water was contaminated [=polluted] with chemicals. ▪ Be careful not to allow bacteria to contaminate the wound. ▪ Don't touch the microchip or the oil on your hands will contaminate it. ▪ Make sure the white paint is not contaminated by any of the other colors. — often used figuratively ▪ The election process has been contaminated by corruption. ▪ Racist ideas have contaminated their minds.
▪ The water was contaminated [=polluted] with chemicals. ▪ Be careful not to allow bacteria to contaminate the wound. ▪ Don't touch the microchip or the oil on your hands will contaminate it. ▪ Make sure the white paint is not contaminated by any of the other colors. — often used figuratively ▪ The election process has been contaminated by corruption. ▪ Racist ideas have contaminated their minds.
— contaminated adjective [more contaminated; most contaminated]
▪ contaminated food/water
▪ contaminated food/water
— con·tam·i·na·tion /kənˌtæməˈneɪʃən/ noun [noncount]
▪ contamination of the water by chemicals ▪ Clean the wound and bandage it to prevent contamination.
/kənˌtæməˈneɪʃən/ noun [noncount] ▪ contamination of the water by chemicals ▪ Clean the wound and bandage it to prevent contamination.
