咁我哋不妨睇睇朗文辭典嘅講法
https://www.ldoceonline.com/dictionary/professor
[British English] a teacher of the highest rank in a university department
[American English] a teacher at a university or college
基本上英式同美式最大分別係,英式professor係"最高"級別,所以你做咗professor之後,職級名銜嚟講就無得再升;而美式professor可以包括埋tutor
即使樓主係講緊英式,樓主都要諗諗"最高"級別代表咩? 係咪一定要讀doctor先可以上到呢個所謂嘅最高級別呢? 樓上有巴打用law professor做例子,正正反映咗英式professor未必係doctor