To Limit
transitive verb, godan verb
Because the hiragana ends with an う sound, you know this word is a verb. The kanji itself means limit so the verb vocab version is to limit.
かぎる
Since this word consists of a kanji with hiragana attached, you can bet that it will use the kun'yomi reading. You didn't learn that reading with this kanji, so here's a mnemonic to help you: to limit things, you have something called a car (か) guillotine (ぎ) which you drive around limiting everything with.
やっぱり、日本語の勉強はTofuguに限るよ。
After all, nothing beats Tofugu when it comes to learning Japanese.