Unitary as a noun
Blog of the Isotopes (noreply@blogger.com)
Since working in the field of quantum computing, I've had to get used to seeing the word unitary used as a noun to mean a unitary object such as an operator or matrix.
Such a usage has yet to make it into any English dictionary that I've checked - not OED, Chambers, Cambridge, Merriam-Webster. Of those, only OED do list one kind of nounal usage, with the definite article, meaning "that which is unitary" with a first example quotation give as:
Man loves the Universal, the Unchangeable, the...