a superlative of old.

far advanced in the years of one's or its life

an old man; an old horse; an old tree.

of or pertaining to the latter part of the life or term of existence of a person or thing

old age.

as if or appearing to be far advanced in years

Worry had made him old.

having lived or existed for a specified time

a man 30 years old; a century-old organization.

having lived or existed as specified with relation to younger or newer persons or things

Jim is our oldest boy.

having been aged for a specified time

This whiskey is eight years old.

having been aged for a comparatively long time

old brandy.

long known or in use

the same old excuse.

overfamiliar to the point of tedium

Some jokes get old fast.

belonging to the past

the good old days.

having been in existence since the distant past

a fine old family.

no longer in general use

This typewriter is an old model.

acquired, made, or in use by one prior to the acquisition, making, or use of something more recent

When the new house was built, we sold the old one.

of, pertaining to, or originating at an earlier period or date

old maps.

prehistoric; ancient

There may have been an old land bridge between Asia and Alaska.

( initial capital letter ) (of a language) in its oldest known period, as attested by the earliest written records

Old Czech.

experienced

He's an old hand at welding.

of long standing; having been such for a comparatively long time

an old and trusted employee.

(of colors) dull, faded, or subdued

old rose.

deteriorated through age or long use; worn, decayed, or dilapidated

old clothes.

Physical Geography . (of landforms) far advanced in reduction by erosion or the like.

sedate, sensible, mature, or wise

That child seems old beyond his years.

(used to indicate affection, familiarity, disparagement, or a personalization)

good old Bob; that dirty old jalopy.

Informal . (used as an intensive) great; uncommon

a high old time.

former; having been so formerly

a dinner for his old students.

( used with a plural verb ) old persons collectively (usually prec. by the )

appropriations to care for the old.

a person or animal of a specified age or age group (used in combination)

a class for six-year-olds; a horse race for three-year-olds.

old or former time, often time long past

days of old.