[いっせいちだい;いっせいいちだい(ik), isseichidai ; isseiichidai (ik)] (n, adj-no) once in a lifetime; the first and last occurrence (event, experience) of one's lifetime
[けいえいいちにょ, keieiichinyo] (n) being inseparable as a form and its shadow; a person's deed mirrors the good or evil of his mind; husband and wife being never apart