geriatrics; geriatric medicine
Medical specialty focused on the health and care of elderly people. The term 老年医学 (ろうねんいがく) is a more common synonym.
See also: 老年医学
Geriatrics is a field that studies the prevention and treatment of diseases in the elderly.
More common term for geriatrics; 老人病学 is less frequent but carries the same meaning.
Compound of 老人 (ろうじん, 'elderly person') + 病 (びょう, 'disease') + 学 (がく, 'study'). The exact historical derivation is uncertain, but the components transparently form the meaning 'study of diseases of the elderly'.