What does 'beamish boy' mean in Jabberwocky?

Oh, dude, 'beamish boy' in Jabberwocky basically means like a super cheerful and excited young dude. It's like the poem's way of saying the boy is all happy and full of energy, ready to take on whatever crazy creatures come his way. So, yeah, it's just a fancy way of saying the kid's in a good mood.