bobber
/ˈbɒbər/Definitions
1. noun
A floating device, especially a buoyant object that marks a fishing line or lure below the water.
“The fisherman attached a bobber to the end of the line to indicate when the fish bit.”
2. verb
To float or bob on the surface of a liquid, especially water.
“The cork bobber floated gently across the pond’s surface.”