It is uncommon. And a bit awkward to say. What if I told you knowing about this word nomological might help you better understand other people?
The dictionary definition of nomological is:
♦️ relating to or expressing basic physical laws or rules of reasoning.
According to revolvy:
♦️ In philosophy, nomology is concerned with the thinking process of the mind. In the mid-19th century, nomology was described as one of two grand divisions of philosophy, the other being metaphysics. The word nomology is made up of -ology suffix for ‘order’, ‘word’ and ‘reason’. The nom- part is ‘rule’ and ‘law’, and means being objectively lawful (i.e. predictably following laws of logic, as in economics).
Mmm, I thought definitions were supposed to help you work out what a word meant. I've got another approach for this word.