痛切
つうせつ · tsuusetsu · JLPT N1 · noun
keen
痛 — sickness radical 疒 + 甬 (yǒng, phonetic)
痛 is a semantic-phonetic compound. The 疒 radical depicts a person on a sickbed and signals illness or pain. The component 甬 supplies the sound, historically close to 'tòng'. Together they convey bodily ache, later extended to emotional pain and the adverbial sense 'thoroughly'.
切 — 七 (phonetic) + 刀 (knife radical)
切 is a semantic-phonetic compound: 刀 'knife' gives the meaning of cutting, while 七 supplies the sound. The original sense was to slice or cut with a blade. From there it extended figuratively to 'close to' (as in pressed against) and 'urgent/earnest', as in 切实.