car

The root car braids together two Latin strands that both circle the same idea — something moving across ground.

The first strand is the verb currere, 'to run, to flow.' Picture a Roman messenger sprinting down a road, or a river running to the sea. From currere English inherited a whole grammar of motion, where the prefix tells you the direction of the running:

- ob- (toward, into the way of) + currere → occur: something 'runs up to' you — it happens, it comes to mind.
- re- (back, again) + currere → recur: it runs back, it happens again. (recurrence, recurrent, recurring)
- con- (together) + currere → concur: minds run together — they agree (concurrent, concurrence).
- in- (onto) + currere → incur: you run into something unwanted — debt, costs, blame.
- ex- (out) + currere → excursion: a running out, a trip away from home.
- pre- (before) + currere → precursor: one who runs ahead — a forerunner, a sign of what's coming.

When something is currently running, it is current — and the same word names a river's flow, an electric flow, and the present moment ('what is running now'). The money that 'runs' through an economy is currency.

Latin formed a noun from the past participle cursus ('a run, a course'). Through Old French this softened into course — first a running track, then any path or sequence: the course of a river, the course of events, and finally a course of study. The most surprising child of cursus is curriculum — in Latin a small racing chariot or its lap; in modern schools, the 'track' a student runs through a program. The handwriting style cursive is writing that 'runs' continuously without lifting the pen; a cursor is the little runner darting across your screen; cursory means done at a run — too quickly to be thorough.

The second strand is carrus, a Celtic word the Romans borrowed for a four-wheeled wagon. This is the heavy, physical, load-bearing side of the family. Carrus gave car (originally any cart or chariot; only later shortened from 'motor car' to mean the automobile), cart, cargo (a wagon's load), carriage (the thing that carries, and by extension how a person carries themselves), and carrier (one who carries).

Two members jump surprisingly far from their literal start. Career comes from the same idea of a racetrack (French carrière): first it meant a full-speed gallop down a course — to career down a hill is to rush wildly — and then, metaphorically, the 'course' you run through your working life. Charge comes from Late Latin carricare, 'to load a wagon' (carrus + -icare). Loading became a chain of meanings: to load a weapon, to load someone with a duty (charge them with a task), to load them with blame (charge with a crime), to load a bill (the charge on your account), and to load up energy (charge a battery). Even a cavalry charge is loading forward at full speed.

The rule across the whole family: whether something runs (currere) or is carried on wheels (carrus), the prefix tells you where it is going.