free from doubt or reservation; confident; sure

I am certain he will come.

destined; sure to happen (usually fol. by an infinitive)

He is certain to be there.

inevitable; bound to come

They realized then that war was certain.

established as true or sure; unquestionable; indisputable

It is certain that he tried.

fixed; agreed upon; settled

on a certain day; for a certain amount.

definite or particular, but not named or specified

A certain person phoned. He had a certain charm.

that may be depended on; trustworthy; unfailing; reliable

His aim was certain.

some though not much

a certain reluctance.

Obsolete . steadfast.

certain ones

Certain of the members declined the invitation.

for certain

without a doubt; surely

I know for certain that I have seen that face before.

adjective

doubtful , doubting , hesitant , uncertain , unconfident , unsure , dubious , faltering , questionable , unreliable , undecided , unfixed , unpredictable , doubtful. seeuncertain , indefinite

adjective

assertive , assured , believing , calm , cocksure , convinced , positive , questionless , sanguine , satisfied , secure , self-confident , sure , unconcerned , undisturbed , undoubtful , undoubting , unperturbed , untroubled , absolute , ascertained , authoritative , clear , conclusive , confirmable , definite , demonstrable , destined , determined , establishable , evident , firm , fixed , genuine , guaranteed , having down pat , incontrovertible , indubitable , infallible , in the bag * , irrefutable , known , on ice , plain , predestined , provable , real , reliable , safe , salted away , set , sound , supreme , sure thing * , true , trustworthy , unambiguous , undeniable , undoubted , unequivocal , unerring , unmistakable , verifiable , bound , certified , concluded , decided , ensured , established , insured , settled , stated , stipulated , warranted , a couple , a few , defined , divers , express , individual , many , marked , numerous , one , particular , precise , regular , several , singular , some , special , specific , specified , sundry , upwards of , various , flat , inescapable , inevitable , unavoidable , hard , inarguable , incontestable , indisputable , unassailable , undisputable , unquestionable , unfailing , confident , acataleptic , actual , adamant , apodictic , categorical , exact , explicit , inerrable , irrefrangible , probabilistic , proved , unmistaken