From pettish + -ness.
pettishness (countable and uncountable, plural pettishnesses)
- The state of being pettish; peevishness, irritability. [from 17th c.]
- 1817, Walter Scott, Rob Roy, XVI:
- The sense that she was observed, or, more properly speaking, that she was watched by my looks, seemed to give Diana a mixture of embarrassment, pain, and pettishness.