Definitions of jet:

noun: an airplane powered by one or more jet engines
noun: the occurrence of a sudden discharge (as of liquid)
noun: a hard black form of lignite that takes a brilliant polish and is used in jewellery or ornamentation
noun: an artificially produced flow of water
noun: street names for ketamine
verb: issue in a jet; come out in a jet; stream or spring forth
Example: "Water jetted forth"
verb: fly a jet plane
adjective: of the blackest black; similar to the color of jet or coal