Posistor is a specialized term used to describe a positive temperature coefficient (PTC) thermistor, which refers to a type of resistor whose resistance increases with increasing temperature. Although "posistor" is the commonly accepted term, there are alternative synonyms that can be used interchangeably in certain contexts. One synonym is "PTC thermistor", where PTC stands for positive temperature coefficient. This term emphasizes the resistance change associated with temperature variations. Additionally, "positive thermal coefficient resistor" can be used. This synonym highlights the resistor's response to temperature changes. While these synonyms represent the same device, their usage may vary depending on the technical focus or the appropriateness for specific discussions.