to believe especially on uncertain or tentative grounds; "Scientists supposed that large dinosaurs lived in swamps"特に不確かであるか仮の根拠で信じる類推
invest at a risk; "I bought this house not because I want to live in it but to sell it later at a good price, so I am speculating"リスクを伴って投資する先物買い
reflect deeply on a subject; "I mulled over the events of the afternoon"; "philosophers have speculated on the question of God for thousands of years"; "The scientist must stop to observe and start to excogitate"主題に関して深く考える考え抜く
talk over conjecturally, or review in an idle or casual way and with an element of doubt or without sufficient reason to reach a conclusion; "We were speculating whether the President had to resign after the scandal"疑問のある、あるいは結論に達する十分な理由のない要素について推測で議論する、意味のないあるいはカジュアルな再考を行う推測