nominalization (grammar)
Definition - The deriving of a noun phrase from a finite clause.

Example -
The finite clause they rejected my application becomes the noun phrase their rejecting of my application.

Etymology -
The word ultimately derives from the Latin nominalis, pertaining to a name or names.

Oxford English Dictionary -
The first citation for the word nominalize (to convert into a noun) is from 1659:
"Verbs … nominalized, do admit one termination familiarly, that suffer not another."
(Instructions Oratory 32)

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