Definition of "coining"

Poetry admits of greater latitude than proſe, which with reſpect to coining, or, at leaſt, new-compounding words; yet, even here, this liberty ſhould be uſed with a ſparing hand.

1783, Hugh Blair, edited by George Edward Griffiths, The Monthly Review‎, volume 68, Art. V. Lectures on Rhetoric and Belles Lettres., page 499

Once we move into the Patristic period, there is undoubted evidence for new coinings of words (particularly compounds) as a response to the needs of the theological debates which occurred.

1989, G.H.R. Horsley, “The Greek Documentary Evidence and NT Lexical Study: Some Soundings”, in New Documents Illustrating Early Christianity‎, volume 5, page 77

Coinings or neologisms are words that have recently been created. […] True coinings, which are completely new words, are rather rare relative to the vast number of words we create by means of the other word formation processes.

2009, Kristin Denham, Anne Lobeck, “Morphological Typology and Word Formation”, in Linguistics for Everyone: An Introduction‎, page 194