There are several synonyms for the phrase "be on edge," which means feeling nervous, anxious, or tense. One such synonym is "be anxious," which refers to a heightened state of worry or unease. Another synonym is "be jittery," which signifies feeling restless or agitated. Similarly, the phrase "be nervous" connotes a sense of apprehension or uneasiness. Likewise, "be uneasy" emphasizes a sense of discomfort or disquietude. Finally, "be on pins and needles" highlights a sense of heightened alertness or anticipation. All of these synonyms convey a sense of tension and unease, reflecting a state of psychological discomfort or anxiety.