Beforehand
In Advance, Previously, Ahead Of Time
adverb
The kanji and the word are almost exactly the same. That means they share meanings as well.
あらかじめ
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:
What did you do beforehand? You had a raw casual (あらかじ) encounter with a raw Cage, Nic Cage. You probably should have planned something better ahead of time.
こうなることは分かっていたので、予め用意しておきました。
I knew it would happen, so I prepared ahead of time.
ひ行きに乗りおくれないように、予め前日にオンラインでチェックインしておきました。
I checked in online a day before the flight so that I wouldn't miss it.
予め予習しておいた甲斐がありました。
Preparing the lesson in advance was worthwhile.