S0654100 (splĭ-nĕt′ĭk) also sple·net·i·cal(-ĭ-kəl)adj.1. Of or relating to the spleen.2. Affected or marked by ill humor or irritability.n. A person regarded as irritable.[Late Latin splēnēticus, from Latin splēn, spleen; see spleen.]sple·net′i·cal·ly adv.EncyclopediaSeesplenetic