追溯
zhuī sù · HSK 7
to trace sth back to
🌊 追 chase + 溯 go upstream (water 氵) = chase a river backward to its source
追 means chase/pursue; 溯 carries the water radical 氵 and means to move against the current. Together: follow something back upstream to where it began, hence to trace back or date from.
追 — 辶 (walk) + 𠂤 (small mound/heap)
Originally a semantic-phonetic compound: 辶 ('walk/movement') gives the meaning of going after something, while 𠂤 supplied the ancient sound. Early bronze inscriptions show it meaning to chase or pursue an enemy. The modern senses — 'pursue,' 'chase after,' 'retroactively' — all extend from this original idea of following in motion.