‘叨光’ (tāo guāng) is a humble, polite expression used when one benefits from someone else’s favor, hospitality, or resources—especially in social situations. Literally, 叨 (tāo) means 'to partake of' or 'to take advantage of', and 光 (guāng) here means 'favor', 'grace', or 'brightness'—a metaphor for the other person’s virtue or generosity. Together, the phrase conveys modesty and gratitude, acknowledging that one’s gain comes solely through another’s kindness.

This term is commonly used in spoken and written Chinese when accepting invitations, dining with others, receiving help, or attending events hosted by someone more senior or respected. It reflects Confucian values of humility and reciprocity. While not archaic, it carries a formal or courteous register—more frequent among older speakers or in semi-formal settings like banquets, business lunches, or family gatherings where etiquette matters.