Jealousy is a complex emotion that can be difficult to fully express or describe in words. However, there are many synonyms for the phrase "be jealous" that can help to capture the essence of this feeling. For example, you might say that someone is envious, covetous, resentful, or possessive if they are experiencing jealousy towards another person. Other synonyms might include phrases like "green with envy," "spiteful," or "jealous-hearted." Overall, there are many ways to describe jealousy and its associated emotions, and choosing the right words can help to convey these feelings more effectively.