脑洞大开 nǎodòngdàkāi highly imaginative Origin Definitions Defs Strokes Stroke Words Sentences Sents 脑 腦 nǎo noun brain The brain of a person or animal; the organ in the head that controls thought and movement.洞 dòng noun hole hole; cavity; cave大开 大開 dàkāi verb to greatly expand to significantly broaden or expand something (such as one's knowledge, outlook, or horizons), as in the phrase 大开眼界 dàkāiyǎnjiè