chin, jaw
頤 centers on the lower face: the chin and jaw. It refers to the bony structure that frames the mouth and supports the lower teeth.
頤 is a phono-semantic compound with 頁 (head) on the right and 巸 (a component associated with the sound イ) on the left, together indicating the chin or jaw area of the head.
The right side 頁 means 'head' or 'page', and the left side looks like a chin with a jawline. Picture a head with a prominent chin: 頤 is the chin and jaw.
For イ, imagine an eagle (イーグル) with a sharp chin: the 'イ' from eagle cues the reading, and the bird's beak points to the jaw.