航行 (háng xíng) is a verb meaning 'to sail' or 'to navigate', referring specifically to the act of traveling by water—especially over long distances or open seas—using a ship, boat, or other watercraft. The first character 航 (háng) means 'to sail' or 'navigation' and often appears in words related to maritime travel (e.g., 航海 hánghǎi 'seafaring', 航线 hángxiàn 'shipping route'). The second character 行 (xíng) means 'to go' or 'to move', reinforcing motion. Together, they emphasize purposeful, controlled movement across water, typically implying planning, skill, and sometimes commercial or exploratory intent.

This word is commonly used in formal, technical, or descriptive contexts—such as maritime reports, news about shipping or naval operations, or historical accounts of exploration. It is rarely used for casual short trips on lakes or rivers; for those, 游泳 (yóuyǒng 'to swim') or 划船 (huá chuán 'to row a boat') are more appropriate. 航行 carries a sense of scale, duration, and intentionality, distinguishing it from general movement verbs like 走 (zǒu) or 去 (qù).