当て字
あてじ · ateji · JLPT N1 · noun
fictional character
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.
字 — roof 宀 + child 子
Originally depicted a child 子 under a roof 宀, suggesting birth or rearing a child in the home. The meaning later extended to 'to give birth, nurture' and then to 'written character', since characters were seen as offspring derived from earlier pictographs.