Could be so many unseemly things:

  • A dead body (see Stephen King's IT)
  • A poo that won’t go down (aka a “light brown floater”)

In the context of financial arrangements:

  • most often a form of equitable mortgage which hovers over the encumbered assets in question only to clamp down on them when the going gets tough: a floating charge, in other words. To be compared and enviously contrasted with a fixed charge.

A floater might also refer to a floating rate note or a floating rate in the abstract, but this isn't really to be encouraged.

See also