Old age is a stage of life that is characterized by physical and mental decline. The term 'ELD' (3 letters) is often used to refer to someone who is very old. ELDERLINESS (11 letters) is another word for the state of being elderly. STONE (5 letters) is a metaphor for something that is very old or ancient. DOTAGE (6 letters) is a term used to describe the mental decline associated with old age. FATUITY (7 letters) is a term used to describe foolishness or silliness that is often seen in elderly people. SENILITY (8 letters) is a term used to describe the mental decline associated with old age. IMBECILITY (10 letters) is a term used to describe extreme mental decline, often seen in elderly people. SENESCENCE (10 letters) is a term used to describe the process of aging. Senectitude (11 letters) is another word for old age.