elder-ness, seniority: the state of being older than others / an older person, a senior

幾多: many

平安: an abbreviation for 平安京 (へいあんきょう, heiankyō), 平安時代 (へいあんじだい, heianjidai), 平安朝 (へいあんちょう, heianchō), or another name of Kyoto

suddenly, unexpectedly