I flew about a dozen DL transcons during last fall/December.

Invariably, if the plane encountered turbulence, the pilot would come on the PA and say "please make sure your seat belts are fastened", or "Flight attendants, please discontinue service" due to not turbulence, but "rough air."

On AA, CO, NW, I always hear them call a spade a spade--"turbulence".

Did I just catch some obtuse pilots, or does DL have a policy against using the word "turbulence?" The only thing I can think of is some silly legal reason (trying to avoid liability, etc.)