There is a briefing sheet made by BA out there with a list of words you shouldn't use and words you should use instead.
They did a pax survey and found that certain words put the fear of god up some but others don't.
Ie they don't like the mention of what speed you are doing but don't mind the altitude.
Don't mention turbulance on arrivial refer to it as a few bumps. The fact that a few bumps might mean you can hardly focus on the instruments because your eye balls are getting bounced around in there sockets dosn't matter.
Its quite a good sheet unfortuantly mine was a 10th generation copy and went walk about after my jacket went to the dry cleaners.
MJ