Real Dictionary

float
countable noun: A float is a light object that is used to help someone or something float.
countable noun: A float is a small object attached to a fishing line which floats on the water and moves when a fish has been caught.
verb: If something or someone is floating in a liquid, they are in the liquid, on or just below the surface, and are being supported by it. You can also float something on a liquid.
verb: Something that floats in or through the air hangs in it or moves slowly and gently through it.
verb: Something that floats lies on or just below the surface of a liquid when it is put in it and does not sink.

float in American English
anything that stays, or causes something else to stay, on the surface of a liquid or suspended near the surface
intransitive verb: to rest or remain on the surface of a liquid; be buoyant
noun: something that floats, as a raft
transitive verb: to cause to float

float in Automotive Engineering
noun: A float is a floating part of a fluid system, such as a carburetor or a fuel level gauge.

float in British English
noun: something that floats
verb: to rest or cause to rest on the surface of a fluid or in a fluid or space without sinking; be buoyant or cause to exhibit buoyancy

float in Finance
verb: If you float a company, you sell shares in it to the public.

float in Retail
noun: The float is a sum of money in a cash register used to provide change at the start of the day’s business.