Outside
Outer Side, Exterior
noun, の adjective
The outside side is the outside.
This word uses the kun'yomi readings from the kanji. Since you learned the kun'yomi reading for 外 with the vocabulary, you should be just fine here.
外側に開くと思ったら、内側に開くドアだったんだね。
I thought this door opened outward, but it actually opens inward, I guess.
いつもは外側のポケットにカギを入れておくんですけど...おかしいなぁ。
I usually put the key in the outside pocket though....weird.
このタコ焼き器を使えば、ガスコンロでも外側がカリカリにできますよ！
With this takoyaki maker, you can make the outside crispy even on a gas stove!