old

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Having lived or existed for a relatively long time; far advanced in years or life.
• adjective Relatively advanced in age.
• adjective Made long ago; in existence for many years.
• adjective Of or relating to a long life or to people who have had long lives.
• adjective Having or exhibiting the physical characteristics of age.
• adjective Having or exhibiting the wisdom of age; mature.
• adjective Having lived or existed for a specified length of time.
• adjective Exhibiting the effects of time or long use; worn.
• adjective Known through long acquaintance; long familiar.
• adjective Skilled or able through long experience; practiced.
• adjective Belonging to a remote or former period in history; ancient.
• adjective Belonging to or being of an earlier time.
• adjective Being the earlier or earliest of two or more related objects, stages, versions, or periods.
• adjective Having become slower in flow and less vigorous in action. Used of a river.
• adjective Having become simpler in form and of lower relief. Used of a landform.
• adjective Used as an intensive.
• adjective Used to express affection or familiarity.
• noun An individual of a specified age.
• noun Old people considered as a group. Used with the.
• noun Former times; yore.

from The Century Dictionary.

• In physical geography, far advanced in the geographical cycle: noting a stage in which land-forms have been reduced to small relief and in which all processes of erosion and transportation have become relatively inactive.
• A pivoted attachment of a pump-rod to a bell-crank.
• Having lived or existed a long time; full of years; far advanced in years or life: applied to human beings, lower animals, and plants: as, an old man; an old horse; an old tree.
• Of (a specified) age; noting the length of time or number of years that one has lived, or during which a thing or particular state of things has existed or continued; of the age of; aged: as, a child three months old; a house a century old.
• Of or pertaining to the latter part of life; peculiar to or characteristic of those who are, or that which is, well advanced in years.
• Having the judgment or good sense of a person who has lived long and has gained experience; thoughtful; sober; sensible; wise: as, an old head on young shoulders.
• Of long standing or continuance.
• Experienced; habituated: as, an old offender; old in vice or crime.
• Of (some specified) standing as regards continuance or lapse of time.
• Not new, fresh, or recent; having been long made; having existed long: as, an old house; an old cabinet.
• Hence — That has long existed or been in use, and is near, or has passed, the limit of its usefulness; enfeebled or deteriorated by age; worn out: as, old clothes.
• Well-worn; effete; worthless; trite; stale: expressing valuelessness, disrespect, or contempt: as, an old joke; sold for an old song.
• Dating or reaching back to antiquity or to former ages; subsisting or known for a long time; long known to history.
• Ancient; antique; not modern; former: as, the old inhabitants of Britain; the old Romans.
• Early; pertaining to or characteristic of the earlier or earliest of two or more periods of time or stages of development: as, Old English; the Old Red Sandstone.
• Former; past; passed away; disused; contrasted with or replaced by something new as a substitute; subsisting before something else: as, he built a new house on the site of the old one; the old régime; a gentleman of the old school; he is at his old tricks again.
• Long known; familiar; hence, an epithet of affection or cordiality: as, an old friend; dear old fellow; old boy.
• Old-fashioned; of a former time; hence, antiquated: as, an old fogy.
• Great; high: an intensive now used only when preceded by another adjective also of intensive force: as, a fine old row; a high old time.
• The mass of land comprising Europe, Asia, and Africa, in contradistinction to the new continent, consisting of North and South America.
• The form of black letter used by English printers of the sixteenth century.
• In mining, ancient workings: a term used in Cornwall.
• A full-grown male kangaroo.
• A man having habits or opinions considered peculiar to old women.