Floater (noun)

1. Something that floats on water or in air.
2. A worker who is not permanently employed and who is available for temporary or casual work.
3. A vision that appears to float in front of the eye, especially one caused by a small particle of debris or a detached retina.
4. A financial term for a bond or loan whose interest rate is periodically adjusted to reflect changes in a benchmark rate.

Origin:

Late 19th century: perhaps from float + -er.

Examples:

1. The raft was filled with floaters enjoying the sunny day on the lake.
2. She worked as a floater, filling in for employees who were on vacation or sick.
3. The doctor told him that he had a floater in his eye and needed to see a specialist.
4. The company issued a floater bond to take advantage of changing interest rates.
5. The floaters bobbed on the water, soaking up the sun.