Indeed, it is, however, it's also the singular of "jongens":
"het jong": the pup, the young (singular)
"de jongen": the pups, the young (plural)
"de jongen": the boy (singular)
"de jongens": the boys (plural)
In this case, the verb is "eet", which means is must be singular. Hence, it's "the boy".
The trailing -n is eroding. Some people even insist that it doesn't even exist any more. Listen to this sentence here and be the judge whether there's still an "-n" there.
In most accents, the erosion has made this "n" weaker than the same sound in other positions. Don't pronounce it like in "banier" (banner), but pretend you are not sure how to say it (which is probably true) and therefore you're skipping past it somewhat.