Jumping, or passing, from one thing or subject to another, without order, planning, or rational connection; lacking logical sequence.
He wandered round, cleaning up in a desultory way.
Out of course; by the way; not connected with the subject.
I made a desultory remark while I was talking to my friend.
Disappointing in performance or progress.
Leaping, skipping or flitting about, generally in a random or unsteady manner.