Amazon Atlas nose-down elevator deflection?
"Nose-down elevator deflection" is a long winded way to say the elevators moved in the direction that would push the aircraft into a dive.  It's phrased this way because it isn't always clear from flight data recorders whether this was a commanded (pilot input) movement, or uncommanded.

In either case, the elevators were deflected downward, which pushes the tail up and the nose down, and over a fairly long time (in terms of a crash in progress) the aircraft was nosed down by 49 degrees.