hoof, falter, to hesitate
蹢 centers on the foot and its actions: a hoof as the foot of an animal, and faltering or hesitating as an unsteady movement of the foot.
蹢 combines 足 (foot) with 啇, which likely contributes the sound. The exact historical development of 啇 is uncertain, but the character is associated with foot-related actions.
The left side is 足 (foot). Picture a hoof as a hard foot, or a foot that falters and hesitates when stepping on uneven ground.
For テキ, imagine a hoof tapping on a wooden deck: the tapping sound 'teki' cues テキ, and the hoof is the foot of the animal.