Principal
From ACT Wiki
1.
An individual or other legal person represented by an agent.
2.
A legal person acting on their own behalf.
3.
The amount of an investment or a loan, excluding any interest.
When the whole of a loan is drawn down at the start, the principal is simply the amount originally borrowed.
4.
The reference amount of a traded financial instrument, used to determine its future cashflows.
5.
Most important, or largest.
Not to be confused with principle, which is different.
