I did remark, to be sure, that mounting the stairs made her breathe very quick; that the least sudden noise set her all in a quiver, and that she coughed troublesomely sometimes: but I knew nothing of what these symptoms portended, and had no impulse to sympathise with her.
There are no more uses of "portend" in the book.
Show samples from other sources
I fear the election results portend greater violence in the region.
Few heeded the sign, and not even Bilbo yet had any notion of what it portended.