the stalk, the stem, the foot, the base
啇 centers on the lower part of a plant or object: the stalk, stem, foot, or base that supports the rest.
啇 is a character of uncertain origin. It visually combines 亠, 并, 冂, and 口, but the historical development of these components into the meaning 'stalk, stem, foot, base' is not clearly established.
The top 亠 is like a lid, the middle 并 and 冂 form a container, and the bottom 口 is an opening. Picture a plant's stalk rising from the base opening, supporting the structure above.
For テキ, imagine a stalk so sturdy you can use it as a teak walking stick: teak -> テキ, and the stalk becomes your base support.