This rare kanji has no clear standalone meaning. Treat its meaning as uncertain.
The exact historical development of 耓 is uncertain. It combines 耒 (plow) with 丁, but the role of 丁 is unclear.
Since the meaning is unclear, focus on the shape: a plow 耒 beside a nail-like 丁. Picture an old farming tool with a T-shaped handle.
For テイ, imagine a T-shaped plow handle: the letter T sounds like テイ, and the plow 耒 reinforces the farming tool image.