Does the word "simpleness" actually exist? [closed]

I always thought the word "simpleness" didn't exist and this was even confirmed by some American friends of mine. However, I tried to look it up on some online dictionaries and I was surprised to find out that some of them report this word while others don't. What's the story behind "simpleness"?

Solution 1:

Simpleness does not necessarily mean the same as simplicity.

For example, simple time in music is a time signature (basic rhythm) which is not compound time. Simple time has simpleness, not simplicity.

OED has a number of similar definitions:

simpleness noun

1. Absence of pride, ostentation, or pretentiousness; plain or unassuming disposition or manners.
2. Absence of duplicity or guile; innocence, integrity, guilelessness.
3. a. Deficiency in knowledge or learning, ignorance; also, lack of mental acuteness, intellectual weakness, foolishness.
4. a. Poor or lowly condition; also, lack of elegance or refinement; plainness of dress, etc.
5. Absence of complexity; freedom from complications; simple character.