-hou is a suffix (part added to the end of a word) found in many Channel Islands and Norman names. It is the Norman language version of the Old Norse holmr, meaning a small island, and often found anglicised elsewhere as "holm". It can still be found in modern Scandinavian languages, e.g. Stockholm.
The Norman hommet/houmet also comes from this suffix.
In Parisian French, the equivalent is îlot, which is the same as the English "islet".
