Origin: Latin suffix -able
Questionable has 3 different meanings across 1 category:
subject to question
"questionable motives"
"a questionable reputation"
"a fire of questionable origin"
able to be refuted
"The defendant's alibi was questionable because a witness contradicted his story minutes after he left."
Problematic; open to doubt or challenge.
"The accuracy of his financial records is questionable because several entries lack supporting documentation."
In plain English: Questionable means something is doubtful, suspicious, or not clearly right.
"The source of that money is questionable, so we need to investigate further before spending any more funds."
Usage: Use "questionable" to describe actions, motives, or sources that are ethically dubious rather than simply uncertain. Avoid confusing this adjective with the noun phrase "a question," which refers to an inquiry itself.
From question + -able.