Power brick, power adapter, or USB charger are what come to mind for me.

I gotta say I disagree heavily with your fiancee on dongles. IMO dongles are adapters for data of some kind, not just power from the wall. But to each their own I guess.

The first time I heard the term dongle it was for the little adapter that connected to a PCMCIA card and I gave my buddy shit for using the term because I thought it sounded dumb. Then, on a trip to the local computer store an employee used the same term for the piece and I got to feel like the dumb one. Good times.