I'll take a stab at it.
Commercial is fairly straight forward... goods and services
-- images employed to promote, advertise and sell goods and services. Doesn't have to be 'for profit' but commercial photography in some way facilitates trade.
Editorial is a bit slippery. It should have to do with news and opinion but it's grown over time to encompass just about anything that's informative
... using the word 'informative' very loosely because informative articles, punditry and 'news' are frequently used in as tools in sales and marketing. That's why you frequently see the two terms combined when related to photography.
To me, a commercial/editorial image will be informative, it will communicate an idea or concept... it's an illustration. A good commercial image will also evoke empathethic feelings in the viewer, allowing them to vicariously experience whatever goods or services the image is selling.
From one mallethead to another, that's my stab.
Weird clouds this afternoon...