Note 1 at Ac 16:16: The Greek word used for "soothsaying" is the word "MANTEUOMAI," and it means "to divine, i.e. utter spells (under pretense of foretelling)" (Strong's Concordance). This is the only time it is used in the New Testament. It differs from sorcery in the sense that soothsaying is fortune telling, while sorcery is all forms of witchcraft in the casting of spells and the using of drugs, potions, charms, amulets, etc.

This soothsaying would correspond to all the ungodly ways people seek to predict the future today, such as horoscopes, reading of tea leaves, tarot cards, reading of palms, crystal balls, and on and on. This girl who did these things was demon-possessed, and so are those who claim to have these powers today.