A kick-arse Irish ale, reddish-brown in colour and with a fairly strong flavour but little aftertaste.
Distributed and owned by Guinness, though it is brewed by a separate brewery in Ireland.
The proper pronunciation, in North America, is "smithicks", and in Ireland, "smiddicks". (Emphasis on the first syllable in both cases.) Anybody who pronounces the w is obviously uncultured and ignorant of the finer things in life.
One of the possible ingredients for a traditional Irish black and tan.