Wifebeater is a slang term in the UK and Australia for Stella Artois beer.
It appears that the term may have originated as a reference to A Streetcar Named Desire (thanks to dutchess and WaldemarExkul for pointing this out).
No doubt this says something about the stereotypical person who drinks large quantities of Stella - they tend to become somewhat aggressive and violent. Rumour has it that Stella has more chemical additives than other beers, which could have something to do with this. This would also explain the terrible hangovers experienced after consuming too much (affectionately known as Stella Head).
Other nicknames for Stella are fight-juice and fighting-fluid.