Some common synonyms of robust are hale, healthy, sound, well, and wholesome. While all these words mean "enjoying or indicative of good health," robust implies the opposite of all that is delicate or sickly.

// a lively, robust little boy

In some situations, the words well and robust are roughly equivalent. However, well implies merely freedom from disease or illness.

// she has never been a well person

The meanings of healthy and robust largely overlap; however, healthy implies full strength and vigor as well as freedom from signs of disease.

// a healthy family