horse about（around）
今回は、久しぶりに見た映画『スパイダーマン3』から取り上げます。
Peter Parker: You're trash, Brock.
Eddie Brock: Excuse me?
Peter Parker: [Peter drops evidence on Eddie's desk revealing that his picture had been modified] Your picture's a fake.
Eddie Brock: Oh, Parker, you are such a boy scout. When are you going to give a guy a break?
Peter Parker: [Peter grabs Eddie and pushes him into his framed fake picture; Bugle workers all look at them] You want forgiveness? Get religion.
Joseph 'Robbie' Robertson: What's going on here?
Miss Brant: Are you guys all right?
Eddie Brock: Yeah. No, we - We're just horsing around.
注目するのはhorsing aroundです。
手持ちの辞書で調べると、horse aroundはhorse aboutともいい、意味は「馬鹿騒ぎをする」です(『ジーニアス英和辞典』第四版、大修館)。もともとhorseの原義には「走ったり飛び跳ねる動物」という意味がありますので、
「まるで馬みたいに走り回ったり飛び跳ねたりする」ということでしょうか。(Sugar)
