Okay, this is a tough word to say, and can be a little tough to understand. Took me awhile.
Basically means taking something that isn't human and giving it human traits, like jealousy or bravery or loyalty. Examples:
Death (as in the cloaked guy with the sickle)
Old Man Winter (icicle-encrusted annoying old dude)
computers (My computer has it in for me...)
dogs (My dog is so loyal...)
In addition, all sorts of gods. From Loki to Zeus to the Christian God, they're all anthropomorphic representations.
If you're still having trouble, read just about any book by Terry Pratchett. In his Discworld books, the anthropomorphic representations are real because people believe in them. Death, especially, is... ah... interesting. Hilarious, actually.