to believe especially on uncertain or tentative grounds; "Scientists supposed that large dinosaurs lived in swamps"
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"
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"
render capable or able for some task; "This skill will enable you to find a job on Wall Street"; "The rope enables you to secure yourself when you climb the mountain"