In modern English usage, the word "fretful" is most commonly used to describe someone who worries a lot; who spends long hours chewing over a problem and is unable to push the worrying thoughts to the back of their mind for any length of time.
The word is not usually used to mean irritable or complaining these days, though it did have that alternative meaning in Shakespeare's time.
The word is not usually used to mean irritable or complaining these days, though it did have that alternative meaning in Shakespeare's time.