Noun

(en noun)

A person with extensive knowledge or ability in a given subject.

* If an expert''' says it can't be done, get another '''expert . -

* {{quote-magazine, date=2013-07-20, volume=408, issue=8845, magazine=(The Economist)

, title= Welcome to the plastisphere , passage=Plastics are energy-rich substances, which is why many of them burn so readily. Any organism that could unlock and use that energy would do well in the Anthropocene. Terrestrial bacteria and fungi which can manage this trick are already familiar to experts in the field.}}

(chess) A player ranking just below master.