One who frequently engages in excessive complaining, negative banter and/or a genuinely poor and downbeat attitude. Naysayers are distinguished by their tendency to consistently view the glass half empty, make frequent one-way trips to negative town, and constantly emphasize the worst of a situation. They have the capacity to rant and whine for hours on end about the most insignificant inconveniences. They tend to travel solo, but have the keen ability to spread their pessimistic attitude to a group of unsuspecting bystanders and encourage others to employ their mindset.
Naysayers tend to blend in with those around them rather well, granted they have learned over the years to adapt to their surroundings. However, when the opportunity arises, their true nature will be exposed and they will stop at nothing to exclude others or bring a general sense of negativity to any situation.