Foys, also spelled as "fice" or "fice dog", is a term used for a small, irritable dog. While it may be an uncommon term, there are several synonyms that can be used in its place. These include "yappy", "snappy", "pooch", "little dog", and "ankle-biter". Other options could be "lapdog", "toy dog", or "teacup dog". Depending on the context and tone of the sentence, any of these substitutes could be used to create a more familiar and easily understood phrase.