I know one says an act of desperation, but I’ve heard desperacy much more than I’ve ever heard desperation, it’s like I’ve almost never heard desperation.
Why exactly was desperation preferred over desperacy and is there a pattern to noun adjectives ending with -ate?
I wonder where the OP has heard desperacy much more than desperation.
The OED says:
desperacy, n. Obs.
Etymology: < desperate adj., n., and adv.: see ‑acy suffix.
- 1629 J. Gaule Practique Theories Christs Predict. 11
Downe to the nethermost depth beyond recouerie: Let vs there take our portion of desperacie.
- 1798 Ann. Reg. (Otridge ed.) Hist. Europe 155/2
Such deeds of desperacy and revenge.
- 1800 W. E. J. Obi 231
Deeds of desperacy and cruelty.
It is not that that desperacy is not an English word. It is not a current English word.