In George Eliot's 1871-2 novel Middlemarch, she uses the word 'worreting.' To the ear of a modern English speaker familiar with the words 'worry' and 'fret,' 'worret' sounds like an additional synonym for those. 'Worret' certainly suggests a ruminating, troubled state of mind. But of course words don't always mean what they sound like they'd mean, so I headed to a handy dictionary.
Where I found ... no listing for 'worret'!
As I have many occasions to use the words worry, fret, fuss and so forth, an additional synonym would be so welcome. Thus, I was a little frustrated. (Traveling, I'm away from my OED, where I'm guessing I will find its definition when I return home.)
However, I located a document on the Internet showing about a half dozen uses of the word in context, all occurring in literature written between about 1875 and 1915. From such context, the meaning of the word can be inferred.
Let's look at a couple or few cases.
The Middlemarch quote is:
Mr. Bulstrode could not enjoy life in their fashion, eating and drinking so little as he did, and worreting himself about everything, he must have a sort of vampire's feast in the sense of mastery.
Eliot also used the word twice in her 1859 novel Adam Bede. For example:
"They mean we shouldn’t be overanxious and worreting ourselves about what’ll happen to - morrow, but do our duty and leave the rest to God’s will."
In his 1871 study called Character, Samuel Smiles uses the word:
They have educated themselves in the habit of endurance, of not being easily provoked, of bearing and forbearing, of hearing harsh and even unjust things said of them without indulging in undue resentment, and avoiding worreting, petty, and self-tormenting cares.
Additional quotes use the word in much the same sense and I think we can reasonably conclude: worret is a lost synonym for worry or fret.