痞 is often used in compounds: 地痞 (local thug), 痞子 (ruffian, scoundrel), 流氓痞子 (hooligan). The character originally referred to a medical condition (abdominal mass), but the colloquial meaning of ruffian is now dominant in everyday use.
疒 pictures a person leaning against a sickbed. As radical it marks 痞 with its older medical sense — a hard lump or obstruction in the abdomen — before the slang sense of ruffian took over. Same radical in 病, 疼, 疯, 症.
否 fǒu/pǐ supplies the sound — 否 has a second reading pǐ meaning blocked or stuck, which 痞 picks up directly. Shared phonetic across 痞 and 否(pǐ) gives a tidy memory hook: blocked breath becomes blocked gut.
