Capital

Etymology

From Latin "capitalis" (of the head), from "caput" (head). Early wealth was counted in heads of cattle, and the “head” sum of a loan or fortune took the same name — the principal from which gains grow. The same root branches into "cattle" and "chattel", other words for countable property.

noun · /KAP-ih-tul/
Wealth — money or assets — used to generate more wealth rather than spent on immediate needs.
What it names
The stock of resources put to work: the cash, equipment, or savings deployed to produce future income rather than consumed today.
Example
They had a promising idea but not enough capital to buy the machinery to start.
Related idea
Distinguish it from income: capital is a stock of wealth held, income is a flow received; capital put to work produces income, and income saved becomes capital.
noun · /KAP-ih-tul/
The city that serves as the official seat of a country's or region's government.
What it names
It separates the political center from the economic sense of wealth — and from the 'capital letter' sense — naming the place where power sits.
Example
Canberra, not Sydney, is the capital of Australia.
Related idea
The capital is the seat of government, not necessarily the largest or richest city — which is why Washington, not New York, is the U.S. capital.
noun · /KAP-ih-tul/
A large-form letter (A, B, C) used to begin sentences and proper names, as opposed to lowercase.
What it names
The ‘big’ form of a letter — the head letter that signals a start, a name, or emphasis.
Example
Write your surname in capitals.
Related idea
Like the capital city and financial capital, this traces to Latin "caput" (head): a capital is literally the ‘head’ letter standing at the front.
adjective · /KAP-ih-tul/
Punishable by death, or involving the death penalty.
What it names
It marks the gravest class of crime and punishment — the offenses the law treats as deserving execution.
Example
In that era, theft could be a capital offense.
Related idea
This too comes from "caput" (head) — originally a crime that could cost you your head — carrying the word’s theme of ‘chief’ or ‘first rank’ over to severity rather than importance.