Harajuku is not a word, it's the name of a place. It's a hip neighbourhood on the Yamanote line, not far from Shinjuku where a lot of young people hang out.
Technically, if you were to deconstruct ナ陳エツ宿 (harajuku), it would mean the "original" (gen, ナ陳エ; also read hara) "inn", "accomodation", or "hotel" (juku, ツ宿ツ); as opposed to Shinjuku (ツ新ツ宿) the "new" (shin, ツ新) "inn", "accomodation", or "hotel", but nobody thinks of "Shinjuku" and "Harajuku" that way, they are just names of places.