With considerable certainty; without much doubt:
— In all likelihood we are headed for war.

synoniemen: belike, in all probability, likely, probably.

Roget 472: probably etc. adj.; belike^†; in all probability, in all likelihood; very likely, most likely; like enough; odds on, odds in favor, ten to one &c.; apparently, seemingly, according to every reasonable expectation; prim=a facie [Lat.]; to all appearance etc. (to the eye) 448.    ... meer laten zien