IPA: /ˈkwɛs.tʃən.ə.bəl/
KK: /ˈkwɛs.tʃən.ə.bəl/
Something that is uncertain, doubtful, or not reliable; it may raise concerns about its morality or truthfulness.
The company's questionable practices led to an investigation.
Questionable → It is formed from "question" (from Latin *quaestio*, meaning inquiry or a matter to be resolved) and "-able" (meaning capable of or worthy of). The word "questionable" means something that is capable of being questioned or doubted.
Think of a 'question' as something you can 'inquire' about, and when something is 'questionable', it means it is worthy of being doubted or asked about.