A buyer broker agreement is a contract with the buyer and the broker to work together for a specified time period to help the buyer find a property.
Posthumous [ a. - Born after the death of the father, or taken from the dead body of the mother; as, a posthumous son or daughter. - Published after the death of the author; as, posthumous works; a posthumous edition. - Being or continuing after one's death; as, a posthumous reputation. Meaning of 'posthumous' (Princeton's WordNet)
Grave, sober, solemn refer to the condition of being serious in demeanor or appearance. Grave indicates a weighty dignity, or the character, aspect, demeanor, speech, etc., of one conscious of heavy responsibilities or cares, or of threatening possibilities: The jury looked grave while studying the evidence.