nài is archaic. It names the largest grade of ritual bronze cauldron (
鼎) — a graded sequence in classical ritual texts runs
鼎 (regular tripod) →
鼒 (small tripod with covered ears) →
鼐 (great tripod). Outside texts on ancient bronzes and ritual studies, the character survives mainly as a personal name. The Qing scholar
姚鼐 (1731-1815) was the leading figure of the Tongcheng school of classical-prose writing — his name preserves the character in living memory.