June 2, 1999

penthouse

How did the word "penthouse" come about?

The word penthouse is a rather wonderful example of our old friend, the folk etymology.

Penthouse is found in a number of forms (as with many words based on folk etymology), but the earliest form was something like pentis, found since the fourteenth century.

This pentis is an aphetic shortening (one where the first syllable is dropped, like lone from alone) of Old French apentis 'an attached building; appendage', ultimately from Latin appendere 'to hang against; attach', also the source of English append and others.

The original meaning of this word was 'a shed with a sloping roof attached to a wall or building', and also 'the sloping roof itself'. Semantically what matters is the attachment of the shed to the larger building.

By the early sixteenth century, the form penthouse arose by folk etymology, with the last element (-is) changed to house to better associate the word pentis with the dwelling-ness of the shed the word denoted. In the early period of the form (mostly the 1500s, less so later), a semantic distinction remained, where pentis was used to refer to the roof only, while penthouse was used for the shed.

The main current sense is 'an apartment or dwelling on the roof of a building', and hence 'any specially designed apartment on an upper floor, esp. the top floor, of a building'. This is first found in the 1920s, a date that seems recent, but which is not that long after large apartment buildings became common.