If you are looking for synonyms for "be furious", there are many options to choose from. One word that comes to mind is "angry", which describes a strong feeling of displeasure or annoyance. Another option is "enraged", which implies a heightened level of anger that may lead to explosive outbursts. "Fuming" suggests an intense anger that is simmering just below the surface, while "livid" refers to a blinding rage that may cause a loss of self-control. "Incensed" expresses a deep and justified anger, while "irritated" describes a more mild form of annoyance that can still lead to frustration. Whatever word you choose, it's clear that the emotion of anger can be felt in many different ways.