売り切れる
うりきれる · urikireru · JLPT N2 · verb-ichidan
to be sold out
🏷️🈵 売り (uri, selling) + 切れる (kireru, to run out) = selling has run out
切れる means to be cut off or run out, the same verb used when a battery dies (電池が切れる). Put 売り, the noun form of 売る (to sell), in front and you get selling that has run out, which means sold out.
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.