keep in one's mind; "I cannot retain so much information"
secure and keep for possible future use or application; "The landlord retained the security deposit"; "I reserve the right to disagree"
allow to remain in a place or position; "We cannot continue several servants any longer"; "She retains a lawyer"; "The family's fortune waned and they could not keep their household staff"; "Our grant has run out and we cannot keep you on"; "We kept the work going as long as we could"
hold within; "This soil retains water"; "I retain this drug for a long time"
establish the validity of something, as by an example, explanation or experiment; "The experiment demonstrated the instability of the compound"; "The mathematician showed the validity of the conjecture"
prove formally; demonstrate by a mathematical, formal proof
obtain probate of; "prove a will"
take a trial impression of
be shown or be found to be; "She proved to be right"; "The medicine turned out to save her life"; "She turned up HIV positive"
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"