A word or phrase may be ambiguous to a translator who will likely only see the string in the interface of their translation tool and not necessarily on the front-end of your theme. Ambiguity can arise when a term is used in more than one context.
The functions _x() or _ex() are used to add the context to a string. They are similar to __() and _e(), but have a comment as an additional argument.
The function can be used in differnt ways
- Explain the use for words with double meaings
- Give extra information about the string