mouseover
nounUK /ˈmaʊsˌəʊvə/
US /ˈmaʊsˌoʊvər/
A mouseover is when you move the computer mouse over something on the screen and it does something.
Hover your mouse over the picture to see a mouseover with its name.
OTHER MEANINGS
2. A web event that happens when the pointer is moved onto an element.
The button changes color on mouseover.
3. A tooltip or pop-up that appears when the pointer rests on an item.
A mouseover showed the definition of the word.
4. In programming, a handler that responds to the pointer entering an element.
They added a mouseover listener to the image.