Antonym of certain

Antonyms of adj certain

7 senses of certain

Sense 1:

certain(prenominal)

INDIRECT (VIA definite) -> indefinite

Sense 2:

certain(predicate) (vs. uncertain), sure (vs. unsure)

uncertain (vs. certain), unsure (vs. sure), incertain
ambivalentdoubtful, dubiousgroping

Sense 3:

certain(predicate) (vs. uncertain)

uncertain (vs. certain)
indefiniteup in the air

Sense 4:

certain (vs. uncertain), sure

uncertain (vs. certain)
chancy, fluky, flukey, iffycontingentup in the air

Sense 5:

sealed (vs. unsealed), certain

Sense 6:

certain, sure

INDIRECT (VIA reliable, dependable) -> unreliable, undependable
INDIRECT (VIA reliable, dependable) -> unreliable, undependable

Sense 7:

certain, sure

INDIRECT (VIA careful) -> careless