When someone is cross, they are typically feeling angry or irritated. Some synonyms for this phrase may include "be annoyed," "be upset," "be mad," or "be irate." These words all describe a similar emotional state where the person is experiencing negative feelings and may be reacting accordingly. Other synonyms for "be cross" might include "be vexed," "be frustrated," "be enraged," or "be incensed." All of these words convey a sense of displeasure or irritation and can be used interchangeably depending on the context and the intensity of the feeling being expressed.