cert
After four wins from their last matches, they look like dead certs for a place in the play-offs.
Not all economists think that a rise in interest rates is a dead cert.
My friend assured me that the horse was a dead cert.

SMART Vocabulary: related words and phrases

Certainty
(as) clear as dayidiom
(as) sure as eggs is eggsidiom
and that's flat!idiom
assure someone of something
assured
deffo
definite
definitely
definitive
definitive answer
ironclad
irrefutable
irrefutably
make no mistake (about it)idiom
mistake
unreserved
unreservedly
watertight
would
you can bet your lifeidiom