When I was a lad, I was told that the cast or forged crankshaft from a multi cylinder engine had journals.
Main journals & rod journals.

The term 'crankpin', apparently, was originally intended to refer to the separately manufactured pin that was used in built up grankshafts, such as might be used in single cylinder engines that were so common in very early automobiles & motorcycles.
The word was to flow into useage with multi cylinder engines as an interchangeable term with rod journal it would seem.

Is this all true? I don't know, but it was what we were taught & it sounds about right to me.