This is a strange word, I'm afraid. You'll have to bear with it. This, when added onto a word, is like adding an "-al" to a word (or a -like to a word). For example, add it onto 日本 (Japan) and you have "Japanese-like," which comes out to "Very Japanese." It's a weird sort of modifying word that really depends on each situation it's in, though -al and -like often do a decent job. For now, just know this word means these things. We'll start applying it to various words in the future, slowly but surely.

The reading is the same as the one you learned with the kanji, probably because this is usually added onto other words, making it behave like a jukugo.