I think it’s more important we talk about mechanics and discuss if they are/aren’t bastard rather than define what bastard is in itself
I’ve seen some players claim that millers/tailors, for example, are bastard - despite this going against years of consensus that I have experienced across multiple communities. “Lies” that are common enough to be predictable and are specifically a mechanic which is accounted for when balancing are not bastard (ie, tailors and millers…)