Translation:The man drinks.
Here is a link that explains this really well. Basically, the whole idea is to make the language flow better from word to word.
This talks about a number of different words where this happens, very helpful: http://french.about.com/cs/pronunciation/a/euphony.htm
They're conjugated forms of the verb "to drink". This will look very confusing, but it is just changing the verb to represent the gender and tense of the action. English doesn't really use this kind of grammar. http://conjf.cactus2000.de/showverb.en.php?verb=boire