The word "waver" refers to the action of being indecisive or showing uncertainty. When someone wavers, they might hesitate between choices or opinions, often causing them to falter or fail to commit. This can also apply to physical movements, such as when an object shakes or fluctuates in position.
The word "waver" comes from the Middle English "waveren," which is related to the Old English word "wafian," meaning to "move to and fro." The term has evolved over time with a focus on both physical and metaphorical senses of uncertain movement or decision-making.