1. 老年病学的；老年医学的
Geriatric is used to describe things relating to the illnesses and medical care of old people.

2. 老年病学；老年医学
Geriatrics is the study of the illnesses that affect old people and the medical care of old people.

3. 老家伙，老头子，老朽（可能具有冒犯意味）
If you describe someone as a geriatric, you are implying that they are old and that their mental or physical condition is poor. This use could cause offence.

1. of or relating to or practicing geriatrics

e.g. geriatric hospital

Synonym: gerontological

2. of or relating to the aged

e.g. geriatric disorder