conclusion, ending, finish - event whose occurrence ends something; "his death marked the ending of an era"; "when these final episodes are broadcast it will be the finish of the show"

quality - an essential and distinguishing attribute of something or someone; "the quality of mercy is not strained"--Shakespeare

cert - an absolute certainty; "it's a dead cert"

ineluctability, unavoidability - the quality of being impossible to avoid or evade

inevitability, inevitableness - the quality of being unavoidable

surety - something clearly established

indisputability, indubitability, unquestionability, unquestionableness - the quality of being beyond question or dispute or doubt

predictability - the quality of being predictable

slam dunk - something that is a sure to occur; a foregone conclusion; "predicting his success was a slam dunk"