祖先
そせん · sosen · JLPT N2 · noun
ancestor
祖 = forebear + 先 = before: ancestors are those who came before
祖 means forebear or grandparent, and 先 means before or earlier. Together they name the people who lived before you in your family line.
先 — 𠂉 (person variant) on top + 儿 (legs) below
先 originally depicted a person with a foot or step shown above the legs 儿, suggesting someone walking ahead. From this image of going before others came the meanings 'first,' 'earlier,' and 'ahead.' The modern shape preserves the 'legs' radical underneath.