当番
とうばん · touban · JLPT N2 · noun
duty
🧹 当 = assigned + 番 = turn in order: your assigned turn to take the job
当 means assigned or appointed, and 番 means turn or number in sequence. Together they name a rotating duty, like cleaning-room duty at school. The word 当番表 means duty roster.
当 — small ⺌ + crown 冖 + hand 彐 (simplified from 當: 尚 + 田)
Originally written 當, combining 田 'field' with 尚 as a phonetic. The early sense was 'to match' or 'face' a field of equal value, extended to 'correspond to', 'ought to', and 'serve as'. The simplified form 当 streamlines the upper 尚 component.
番 — 釆 (animal tracks) on top + 田 (field) below
Originally a pictograph showing animal paw prints (釆) in a field (田), depicting tracks left by beasts. The early meaning related to taking turns or sequences, as tracks come one after another. It later extended to 'foreign' or 'barbarian,' and is now used as a measure word for occurrences or to mean 'number/turn.'