oldest

Concise Oxford English Dictionary © 2008 Oxford University Press:
old/əʊld/

▶adjective (older, oldest)

• 1 having lived for a long time; no longer young.

  ■ made or built long ago.

  ■ possessed or used for a long time.

• 2 former; previous.

• 3 long-established or known: old friends.

• 4 of a specified age.

  ■ [as noun] a person or animal of the age specified: a five-year-old.

• 5 informal expressing affection, familiarity, or contempt: good old Mum.

– phrases
of old

• 1 in or belonging to the past.

• 2 for a long time.

the old country the native country of a person who has gone to live abroad.
the old days a period in the past.
the old school the traditional form or type.

– derivatives
oldish adjective,
oldness noun.

– origin OE ald, of W. Gmc origin.