The most simplest answer would be improbable.
The opposite is "improbable" (unlikely).
improbable
Probable you think to ions but ions are not subatomic particles.
Probable you think to ions but ions are not subatomic particles.
pro
Mingle with females and you probable find one you like. Mingling means talk, ask questions, attend events, be attractive to the opposite .
more probable most probable
probable is an adjective
seem probable
The negative prefix for probable is "im-," so the negative form of probable would be "improbable."
The root word of improbability is "probable," which comes from the Latin word "probabilis," meaning "likely" or "credible." The prefix "im-" is added to form the opposite meaning.
un probable