an unknown and unpredictable phenomenon that causes an event to result one way rather than another; "bad luck caused his downfall"; "we ran into each other by pure chance"
an unknown and unpredictable phenomenon that leads to a favorable outcome; "it was my good luck to be there"; "they say luck is a lady"; "it was as if fortune guided his hand"
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"