"Church mouse" is a commonly used expression meaning someone who is very quiet or poor. There are several synonyms that can be used to replace this expression, depending on the context.
For example, "quiet as a mouse" is an alternative phrase used to describe someone who is very quiet and not likely to draw attention to themselves. Other synonyms for "church mouse" include "meek," "shy," "timid," "reserved," "humble," and "unassuming."
If you want to describe someone who is poor, you can use synonyms like "penniless," "impoverished," "destitute," "needy," or "broke." These synonyms are often used in the context of financial struggles or hard times.
In conclusion, there are several synonyms for "church mouse" depending on the context, including quiet, shy, timid, poor, and humble.