Refers to someone who held a position before the current holder, or the state of having been appointed earlier. Often used in workplace or organizational contexts.
I take over from my predecessor as department head.
Positions are determined by seniority.
predecessor; senior official; senior member
order of seniority
senior officer
Compound of 先 (previous, earlier) and 任 (duty, appointment). The exact historical derivation is uncertain, but the meaning follows naturally from the kanji components.