耳朵 (ěr duō) is the colloquial, everyday term for 'ear' in Mandarin — the external and internal organ responsible for hearing and balance. While 耳 (ěr) alone means 'ear' and appears in formal or compound words (e.g., 耳机 'headphones'), adding 朵 (duō), which literally means 'flower' or 'blossom', creates a vivid, gentle image — evoking the ear’s soft, petal-like shape. This character combination reflects Chinese word formation where a concrete noun (朵) adds visual or affective nuance to an abstract body part.

The term is universally used in spoken Chinese across all ages and regions, especially in informal speech, health contexts (e.g., earaches, cleaning ears), and child-directed language. It rarely appears in highly technical medical writing (where 耳部 or 内耳 may be preferred), but dominates daily conversation, idioms (e.g., 耳朵软 'easily swayed by others’ opinions'), and expressions involving listening or attention.