While I am not familiar with this particular instance, universities will often have a permanent professorship, or chair, with a specific focus that is named either after a renown expert in the field who taught at that institution, or after the person or organization who funded (endowed) the establishment of that position.

As for Loeb himself, I'm only passingly familiar with him in passing because of coverage since ‘Oumuamua, but it seems like he is a fairly typical asgtrophysicist who decided for some reason that he would launch a crusade declaring anything entering the Solar System from interstellar space must be an alien probe or spaceship.

Usually just means the position is sponsored by a donor (in this case Frank B. Baird Jr.). Salary and sometimes other funding gets paid via endowment set up by the named person or someone else on behalf of the named person.

Frank B. Baird Jr. was the son of Frank B. Baird, of Buffalo New York, who died some time around 1947. His son, and Flora M. Baird, his widow, set up a charitable trust in his name which did things like donate to the Buffalo Museum of Science. The later Frank B. Baird Jr. Foundation made several donations to Harvard for scholarships and the like in the 1950s.