Can College Professor (Part-time) have a Full-time job outside of the University?

I am considering doing a PhD. And I do want to teach but after doing the math, I probably will make more money being a consultant/director full-time and teach night classes part-time.

Do universities allow their faculty work full-time outside the university?
If your part-time are you still on a tenture track?
How much do adjacent/PT professors make?
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Yes, almost all professors who teach PT have a secondary job, pretty much all of my professors have(CPA's, consultants, etc). As long as you don't sign an agreement that doesn't allow that type of thing. However, most Universities want their faculty to remain active and relevant in their fields, so they often make concessions so that they can do just that.
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Adjunct and part time faculty are not considered for tenure. Adjunct faculty are usually not professional educators. They are industry professionals whose education and expertise is in the field they teach, and their pay rate is variable depending on their experience and industry reputation. They usually only teach one or two courses a semester. I am not sure about the pay scale of part-time professional teachers at the college level but I am sure it is variable depending on the college and their need for teachers in the specific field.