This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 鼑 is uncertain. It visually combines ⺊ (divination) with 鼎 (tripod kettle), but the original semantic and phonetic roles are unclear.
The top ⺊ suggests divination, and the bottom 鼎 is an ancient tripod vessel. Picture a fortune-teller reading cracks on a heated bronze tripod, but remember the meaning itself is uncertain.
For テイ, imagine a tea (ティー) ceremony using an ancient tripod kettle: tea -> テイ, and the tripod shape of 鼎 holds the tea.