foreign substance; foreign body; contaminant
Used in medical, food-safety, and industrial contexts for unwanted material that does not belong.
A foreign substance was found in the food.
If a foreign body gets into your eye, rinse it out without rubbing.
strange object; unusual item
Refers to an object that is out of place or unexpected, not necessarily harmful.
I found a strange object on the beach.
Archaic literary use for a dead body; not used in modern everyday speech.
In old texts, 異物 can refer to a corpse.
An incident occurred in which a foreign substance was found mixed into food.
The doctor removed the foreign object stuck in the throat.
I felt like there was something in my eye, so I went to see an eye doctor.
死体 is the plain, everyday word for a corpse, while 異物 in this sense is an old literary term for a dead body no longer used in normal speech.
汚染物質 is a technical term for a pollutant or contaminant in an environmental or chemical sense, whereas 異物 is used more generally, including in food-safety and medical contexts.
Sino-Japanese compound of 異 (different, unusual) and 物 (thing, object).
A foreign object was found in the boxed lunch, and the shop suspended business.