clicker
The origin and history of clicker.
Etymology
From "click" — a word imitating a short, sharp sound — plus the agent suffix "-er," giving "a thing that clicks." The animal-training sense is the older one: the term comes from a small metal cricket noisemaker, adapted from a child's toy, used to mark the behaviour a trainer wants. The video-game sense is much newer, emerging in the early 2010s alongside games like Cow Clicker and becoming widespread after Cookie Clicker in 2013.