Splenetically is an adverb that means to act in an irritable or bad-tempered way. Some synonyms for splenetically include angrily, crossly, testily, irately, peevishly, snappishly, grumpily, sullenly, petulantly, and cantankerously. These words all convey a level of frustration and annoyance, indicating someone who is easily irritated or prone to outbursts of anger. Whether it's a bad day, lack of sleep, or just a general sense of frustration, someone acting splenetically tends to be difficult to deal with and quick to snap. Understanding these synonyms can help you better describe this behavior in your writing, portraying characters more effectively or giving voice to your own feelings.