American Tract Society Bible Dictionary
Choice, chosen way of life or faith, sect, school, party. The Greek word properly designates any sect or party, without implying praise or censure. So in Acts 5:17 15:5 26:4,5 . In the epistles it denotes a sect or party in a bad sense, implying a refractory spirit, as well as error in faith and practice, 1 Corinthians 11:19 Galatians 5:20 2 Peter 2:1 . After the primitive age, the word came to signify simply error in doctrine.
These files are public domain and are a derivative of the topics are from American Tract Society Bible Dictionary published in 1859.
Rand, W. W. Entry for 'Heresy'. American Tract Society Bible Dictionary. https://www.studylight.org/dictionaries/eng/ats/h/heresy.html. 1859.