as the agent of or on someone's part (usually expressed as "on behalf of" rather than "in behalf of"); "the guardian signed the contract on behalf of the minor child"; "this letter is written on behalf of my client";
for someone's benefit (usually expressed as `in behalf' rather than `on behalf' and usually with a possessive); "in your behalf"; "campaigning in his own behalf"; "spoke a good word in his friend's behalf"
past times (especially in the phrase `in days of old')
of a very early stage in development; "Old English is also called Anglo Saxon"; "Old High German is High German from the middle of the 9th to the end of the 11th century"
old in experience; "an old offender"; "the older soldiers"
of long duration; not new; "old tradition"; "old house"; "old wine"; "old country"; "old friendships"; "old money"
(used especially of persons) having lived for a relatively long time or attained a specific age; "an old man's eagle mind"--William Butler Yeats; "his mother is very old"; "a ripe old age"; "how old are you?"