Re: Has anybody heard of the name Hanham?
Since you are a New Zealander, this is most likely simply a use of the English surname Hanham as a given name. According to Hanks & Hodges' A Dictionary of Surnames, Hanham goes back to a place name in Gloucestershire, England, which is based on the Old English word hanum, which was the dative plural of a word that meant "rock." So Hanham would originally have meant "rocks" or "rocky place."