Well
noun
A well door is just a well. It's the door that goes into the well hole, making it a well.
This kanji uses the kun'yomi readings for each kanji, for some reason. You learned the kun'yomi reading for both of these kanji as their primary readings already, just watch out for 戸 getting rendaku'd so it becomes ど instead of と.
井戸の外
outside of the well
井戸のそば
near the well
井戸の水
well water
井戸をほる
to dig a well
井戸をうめる
to fill in a well
井戸を作る
to make a well
井戸を使う
to use a well
井戸を調べる
to inspect a well
井戸水
well water
井戸がある
there is a well
井戸が見つかる
a well is found
井戸が使える
the well is usable
井戸に落ちる
to fall into the well
井戸に入る
to go into the well
井戸に落とす
to drop something into the well
あそこに井戸があるよ。
There's a well over there.
井戸に入ってはいけないよ。
You must not go into the well.
え、今、井戸から声がしなかった？
Wait, didn't you just hear a voice coming from the well?
よくひえた井戸水を飲むと、つめたいアイスクリームを食べた時のように頭がキーンといたみました。
When I drank cold water from the well, I got brain freeze like when I ate cold ice cream.