Shamefastly is an old English word that has lost its relevance in modern English. However, it can be interpreted as an old-fashioned synonym for shamefaced. Some other alternatives for the word shamefastly include ashamed, embarrassed, mortified, humiliated, chagrined, abashed, and nonplussed. All these words denote feelings of discomfort or distress caused by something embarrassing or humiliating. While some of these words are more formal, others are more colloquial. Shamefastly was once a popular term, but over time it has become archaic. Nevertheless, its meaning and other synonyms continue to form an essential part of the English language.