Translation of "Improvised" in Japanese

It's a little bit like an improvised grappling hook. Okay.

つかみかぎみたいだな よし

Marshals Lannes and Masséna led  the way across improvised bridges,  

ランヌ元帥とマセナは、 ベシエール騎兵隊の支援を受けて

As the remnants of the Grande Armée began  crossing over two improvised bridges,  

大陸軍の残党が2つの即興の橋を渡り始めたとき、

- It's been decided that the entertainment for our year-end party will be a question-with-comical-improvised-answer session.
- We decided to have a last piece on the programme at the year-end party.

忘年会の余興で大喜利をやることになった。