BJ是Bungee Jumping的缩写

Bungee Jumping

英 [ˈbʌndʒi ˈdʒʌmpɪŋ]

美 [ˈbʌndʒi ˈdʒʌmpɪŋ] 

蹦极;蹦极跳;蹦極;爱情蹦极跳

例句

But I've been crazy about bungee jumping. 
但我对蹦极很着迷。

You wanna come bungee jumping with me and my friends? 
你想加入我和我的朋友们去蹦极吗？

She has no interest in skydiving or bungee jumping or parachuting. She's not especially sporty or athletic. 
她对跳伞或蹦极没什么兴趣，也不是特别健壮或富有运动细胞。