nom

The Greek word nomos is one of those roots whose everyday meaning is bigger than any single English translation. At its core it meant the way things are apportioned — how a herdsman divided up grazing land, how a city divided up power, how custom divided right from wrong. The verb behind it, nemein, simply meant 'to distribute, to manage.' So nomos covered three overlapping ideas at once: law, management, and distribution. When Greek built compound words, that single idea — 'the governing principle of X' — attached itself to whatever came before it.

Start with the most familiar member: economy. Greek oikos (household) + nomos (management) = oikonomia, literally 'household management' — the art of running a home, budgeting its food, dividing its chores. Centuries later that same word scaled up from one household to an entire nation's resources, and 'household management' became 'the economy.' The thrift sense never disappeared: to be economical is to manage resources carefully, exactly as a careful householder would.

Now swap the front piece and watch the pattern hold. auto- (self) + nomos (law) = autonomy: living under laws you set for yourself, self-rule. astron (star) + nomos = astronomy: the laws that govern the motion of the stars. taxis (arrangement, order) + nomos = taxonomy: the orderly system by which we sort living things into kingdoms, classes, and species. agros (field) + nomos = agronomy: the management of soil and crops. In every case the front word names the domain, and nomos says 'this is the governing law or management of that domain.'

There is one outlier worth flagging. Nomadic comes from the same Greek family but through a different doorway: nomas meant 'wandering in search of pasture,' and it traces straight back to nemein, 'to distribute / to put animals out to graze.' A nomad is literally someone who parcels out grazing land by moving across it. So the 'wandering' sense and the 'law/management' sense are cousins, both growing out of the original idea of apportioning land.

Finally, a warning that the methodology insists on: this root looks identical to another one but is not related. The nomin- in nominate, nominal, and denomination comes from Latin nomen, 'name.' Same letters, completely different origin. When the sense is name, you are dealing with nomin-; when the sense is law, system, or management (economy, autonomy, astronomy), you are dealing with this Greek nomos.