Here is a context clues worksheet on the verb portend. It means “to give an omen or anticipatory sign of.” This verb is used only transitively, so don’t forget your direct object: something must portend something else, e.g. “Thunder and lightning portend rain.”
This comes to English from Latin, which is no surprise. The Romans had great faith in portents, and heeded them willingly. In fact, Roman priests sought auguries in the flights of birds. But that’s the subject of another post.
If you find typos in this document, I would appreciate a notification. And, as always, if you find this material useful in your practice, I would be grateful to hear what you think of it. I seek your peer review.