Splenetic refers to something that is irritable, bad-tempered, or grumpy. An antonym for more splenetic could be cheerful which means expressing happiness and positivity. Another antonym could be pacific which means promoting peace and calmness. Additionally, tranquil is an antonym for more splenetic, as it suggests a sense of calmness and relaxation. Serene is yet another antonym, indicating a state of inner tranquility and contentment. Content, peaceful, and genial are other antonyms for more splenetic. By using such contrasting words, you can add depth and dimension to your writing and describe a wide range of emotions with precision.