What does "float" mean?

Additional senses

1. 2.(Tempering) A contrivance for affording a copious stream of water to the heated surface of an object of large bulk, as an anvil or die. Knight.
2. 3.The act of flowing; flux; flow. [Obs.] Bacon.
3. 4.A quantity of earth, eighteen feet square and one foot deep. [Obs.] Mortimer.
4. 5.(Plastering) The trowel or tool with which the floated coat of plastering is leveled and smoothed.
5. 6.A polishing block used in marble working; a runner. Knight.
6. 7.A single-cut file for smoothing; a tool used by shoemakers for rasping off pegs inside a shoe.
7. 8.A coal cart. [Eng.] Simmonds.
8. 9.The sea; a wave. See Flote, n. Float board, one of the boards fixed radially to the rim of an undershot water wheel or of a steamer's paddle wheel; -- a vane. -- Float case (Naut.), a caisson used for lifting a ship. -- Float copper or gold (Mining), fine particles of metallic copper or of gold suspended in water, and thus liable to be lost. -- Float ore, water-worn particles of ore; fragments of vein material found on the surface, away from the vein outcrop. Raymond. -- Float stone (Arch.), a siliceous stone used to rub stonework or brickwork to a smooth surface. -- Float valve, a valve or cock acted upon by a float. See Float, 1 (b).
9. 10.To rest on the surface of any fluid; to swim; to be buoyed up. The ark no more now floats, but seems on ground. Milton. Three blustering nights, borne by the southern blast, I floated. Dryden.
10. 11.To move quietly or gently on the water, as a raft; to drift along; to move or glide without effort or impulse on the surface of a fluid, or through the air. They stretch their broad plumes and float upon the wind. Pope. There seems a floating whisper on the hills. Byron.
11. 12.To cause to float; to cause to rest or move on the surface of a fluid; as, the tide floated the ship into the harbor. Had floated that bell on the Inchcape rock. Southey.
12. 13.To flood; to overflow; to cover with water. Proud Pactolus floats the fruitful lands. Dryden.
13. 14.(Plastering) To pass over and level the surface of with a float while the plastering is kept wet.
14. 15.To support and sustain the credit of, as a commercial scheme or a joint-stock company, so as to enable