Peter,
Here (post #93 in the thread),
http://forums.adobe.com/message/4390337?tstart=0#4390337
is the answer by a sinister insider:
"Trending Questions" is newspeak for "Recent Activity", though not everything that trends is actually a question. You can tell by the color of the speech-bubbble icon.
Further to current senses (1933) according to the OED (the big one), in the figurative sense 4b), to trend is:
- To turn in some direction, to have a general tendency (as a discussion, events, etc.).
And the verbal substantive Trending sense 2):
- The fact or manner of turning, bending away, or taking a (specified) direction, as a coastline, etc.; general direction, trend.
And there is also sense 1b):
- The winding of wool in a top.
The last one may be most accurate: the expression seems to be rather woolly.
