Lock
Noun
かぎ
いや〜鍵を中に置いたまま車に鍵をかけちゃってさ、今鍵屋さんが来るのを待ってるんだよ。
Well, I locked myself out of my car and am waiting for a locksmith to come.
The kanji and the word are exactly the same. That means they share meanings as well.
The reading is the same as the one you learned with the kanji.