What does "foreign body" mean?

An unwanted, intruding object or piece of matter.

What is a synonym for "foreign body"?

Common synonyms include: black sheep, blemish, embolus, impurity, intruder, invaders.

noun

noun ·Rare ·Advanced level

Noun

1
An unwanted, intruding object or piece of matter.
"The foreign body stuck inside the dog's stomach turned out to be a bottle cap."

"The foreign body stuck inside the dog's stomach turned out to be a bottle cap."