Arrange In A Row
Noun, する verb, and の adjective
へいれつ
もし自分の彼氏が後ろ向きで入る並列駐車が上手くできなかったら、がっかりしちゃうと思う。
If my boyfriend was bad at reverse parallel parking I’d be disappointed in him.
Line up everything in a row. When you do that, they're all in a row.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.