"Strong as an ox" is a popular idiom that describes someone who is very strong and sturdy. However, there are several other synonyms that can be used to describe a person's strength. Some of these synonyms include "mighty," "powerful," "robust," "hardy," and "vigorous." These words are often used to describe people who are physically fit and have great endurance. They may also be used to describe people who have mental strength and resilience. Overall, there are many different words that can be used to describe strength and each one can add a unique nuance to the description.