Select the most appropriate meaning of the given Idiom:-

A thorn in the flesh 

A constant source of annoyance

The most appropriate meaning of the idiom "a thorn in the flesh" is a constant source of annoyance. The idiom comes from the Bible, where it is used to describe someone who is a constant source of trouble or pain. In a figurative sense, a thorn in the flesh can be anything that is a constant source of annoyance or frustration.

The other options are not as accurate descriptions of the meaning of the idiom. A critical test is not typically associated with the idiom "a thorn in the flesh." Being in an alien culture is not the same as being a thorn in the flesh. Not belonging to a place is not the same as being a thorn in the flesh.