principal

柯林斯词典

1. ADJ Principal means first in order of importance. 最重要的[ADJ n]
The principal reason for my change of mind is this. 我改变主意的最重要原因就是这个。
...the country's principal source of foreign exchange earnings. …该国最重要的外汇交易收入来源。
2. N-COUNT The principal of a school is the person in charge of the school or college. 校长
Donald King is the principal of Dartmouth High School. 唐纳德·金是达特茅斯中学的校长。
3. N-COUNT The principal of a loan is the original amount of the loan, on which you pay interest. (贷款的) 本金[商业] [usu sing]

The principal aim of this meeting is to reach a decision that we all agree on.
The diaphragm is the principal muscle of respiration .
I would like to earn more, but this isn't my principal reason for leaving the job .
He can't give up teaching , it's his principal source of income .
This is the principal road between the two cities .