I think this is just going to be a discussion of each of our personal definitions, because there is no industry/community wide standard definition for either "hybrid" or "comfort".

The way I look at it (and some others I've talked to) is that a hybrid is a bike with some characteristics of a road bike and some characteristics of a mountain bike (but generally intended predominantly for use on pavement). The category "hybrid" can be further classified into "comfort hybrids" and "performance hybrids." Comfort hybrids are those designed primarily for comfort (as opposed to speed): very upright riding position, often feet forward, curved handlebars, etc. Performace hybrids are sometimes called flat bar road bikes, and have a more upright riding position than a road bike in the drops, but are designed to be fairly efficient and speedy.