Is that right?

[Anonymous]

I saw a film described a women as 'third wheel'. Is that same as so-called third party or adulterer?

Thanks

[Pete]

I saw a film described a women as 'third wheel'. Is that same as so-called third party or adulterer?

Thanks
No, nothing to do with adultery. The image is related to a bicycle. The third wheel is the extra person, more or less unneeded and maybe in the way. Imagine that a couple in a relationship have a date to go to the movies, and a friend invites herself along because she wants to see the movie too and thinks some company would be nice. The original pair might think of her as a "third wheel".

Extending the image to an automobile, when there are more than 3 people involved and one is not wanted by the others, the term "fifth wheel" is often used.