Sincereness vs sincerity. A reader asks, “Is sincereness a word?”
This turns out to be a very interesting question, but probably not for the reasons you think.
The short answer is that “sincerity” is the correct word, and “sincereness” is a non-standard variant. The rest of this answer is the “blah blah blah” that causes my wife to show me the hand.
The answer to “Is X a word?” is always “yes.” A word is a sound or combination of sounds that convey meaning. You speak; I understand: words were used. Irregardless, forshnizzel. Some words are part of the standard English lexicon; others are not yet accepted as standard; while some are obsolete. Forsooth.
Definition of Sincereness
That’s not even the interesting part. Of course, I used Google to help me answer this question. I thought I would find an online source that defined “sincereness” as non-standard. Instead, I found things like Sincereness vs. Sincerity on WikiDiff. WikDiff properly defines “sincerity” and provides “sincereness” as a synonym. But “sincereness” only has one definition: “sincerity.” Likewise, at other sites, I found the results of a Google search taking me to a page that provided the meaning of “sincerity” with or without a mention of “sincereness.” Very useful if you are trying to find out what these words mean; not useful if you are trying to decide which is correct. I also tried asking the difference between dog and cat, just to see how the artificial intelligence would handle it.
What I realized from this adventure is that these pages are generated by artificial intelligence algorithms that fail to understand the nature of the question. When you write “sincereness,” the algorithm recognizes the root of the word and automatically provides the definition to “sincerity”; it misses the little human touch that would include “non-standard” or “this isn’t the right word to use.”
Usage of Sincereness vs Sincerity
However, Google also provided definitive evidence of the difference. I used Google Ngram to look up the relative usage of the two words. I expected to find that “sincerity was used much more often than “sincereness.” In fact, “sincereness” is used so little that it doesn’t even register on the graph. Here’s the graph comparing the two words.
“Sincereness” is the flat blue line across the bottom. Another interesting question is “Why has the use of ‘sincerity’ declined over the last two hundred years?” Is there another word being substituted? Or do we simply write less about being sincere? That’s a rabbit hole I don’t have time to dive down right now.