The word **理睬 (lǐcǎi)**, meaning "to pay attention to" or "to acknowledge," is formed through a common Chinese morphological process called **synonym compounding**. It combines two characters with similar meanings: **理 (lǐ)**, which in this context carries the sense of "to manage" or "to deal with," implying a deliberate engagement, and **睬 (cǎi)**, a character specifically meaning "to pay attention" or "to notice." By pairing these near-synonyms, the compound word **理睬** creates a stronger, more nuanced verb that emphasizes the active act of acknowledging or heeding someone or something, often used in the negative (不理睬, "to ignore") to denote a deliberate lack of response.