"In a flap" is a common phrase used to describe a state of worry or panic that someone may find themselves in. There are plenty of synonyms for this phrase that can be used to more accurately describe the situation. Some examples of phrases that could be used in place of "in a flap" include "frantic," "distraught," "agitated," "anxious," "edgy," and "nervous." Depending on the situation, certain synonyms may more accurately convey the level of panic someone is experiencing. Whatever the case, using a variety of synonyms can help keep writing fresh and varied, while also helping convey more precise meaning.