also: かいご
Archaic word for 'egg' or 'eggshell'. In modern Japanese, たまご is used for 'egg' and 卵の殻 for 'eggshell'. Found only in classical texts or historical contexts.
In classical Japanese, 'kai' meant egg.
In this old document, the notation '卵 (kai)' can be seen.
Archaic kanji spelling for 'egg' or 'eggshell'. The reading かい is rare; modern Japanese uses たまご for 'egg'.
Archaic reading かいご for 卵, meaning 'egg'. Restricted to this kanji form.
Alternate archaic kanji for 'eggshell'. Not used in modern Japanese for this meaning.
Rare archaic kanji for 'eggshell' or 'husk'. Extremely uncommon.
The historical derivation is uncertain. かい is an archaic native Japanese word for 'egg' or 'eggshell', largely replaced by たまご in modern usage.