Principal (finance)
Etymology
From Latin "principalis" (first, chief), from "princeps" (first, foremost). The financial sense treats the base sum as the chief amount, with interest as the secondary thing it produces. Note the homophone "principle" (a rule or belief) — a different word entirely, from Latin "principium".
noun · /PRIN-suh-pul/
The original sum of money borrowed or invested, separate from any interest it earns or costs.
What it names
Reach for it to name the “real” debt or investment underneath — the amount that actually shrinks when you pay down a loan or grows when you save.
Example
Most of her early mortgage payment went to interest, with barely a dent in the principal.
Related idea
Pair it with interest: principal is the debt itself, interest is the rent you pay for using it — early payments are nearly all interest, which is why the balance falls so slowly at first.
noun · /PRIN-suh-pul/
The head of a school.
What it names
the chief administrator of a school
Example
The principal called a school-wide assembly.
Related idea
Not to be confused with principle, a guiding rule: the school principal is a person, and the spelling remembers it — the princiPAL is meant to be your pal.
adjective · /PRIN-suh-pul/
First in importance; main or chief.
What it names
the foremost among several
Example
Her principal reason for leaving was the commute.
Related idea
Note the spelling: the adjective and the school head are ‘principal’; a fundamental rule is a principle.