heresy

From Middle English heresie, via Old French heresie, from Latin haeresis, from Ancient Greek haíresis meaning 'choice, system of principles,' itself from hairéomai, 'to take for oneself, to choose,' the middle voice of hairéō, 'to take.'

What began as a neutral Greek word for making a choice or holding a school of thought narrowed over time into something dangerous: a belief chosen against the accepted one. It also displaced the native Old English word dwild.

It shares a root with hairéō, 'to take,' and is possibly connected to the Proto-Indo-European root behind Welsh herw ('theft, raid') and Greek steréō ('to deprive of') — words all circling the idea of taking or being taken from.