soft rice cooked in a pot
Archaic term for rice cooked soft in a pot, contrasted with 強飯 (kowameshi), which is steamed glutinous rice. Not used in modern everyday language.
See also: 強飯
In old documents, 姫飯 is sometimes contrasted with 強飯.
The exact derivation is uncertain; the kanji 姫 (princess) may be used here as a euphemism for softness or delicacy, but this is speculative.