top cat

1. noun The person with the most authority, power, or influence in a group or organization. When I was top cat of the business, I used to charge the most outrageous things to the company credit card. You'll only get a truthful answer if you manage to talk to one of the top cats.

2. adjective Related to such a person. Typically hyphenated and used before a noun. CEO is a top-cat position, and I really don't think he has enough experience for the job.