one of undefined or unknown sexual preferance.
I like my hairdresser he does a good job, but he sure is questionable.
Un-sure about something, dont know a persons true intentions, unknown.
Is that a guy or a girl? His sex is surely questionable.
Anna Nicole Smith is marrying an old man. Whoa, her intentions are sure questionable.
Whenever a question is able to be formed about a certain idea, principle, or physical thing, and there is concern about its validity, the idea, principle, or physical thing has become questionable.
"Kevin, did you see that girl? She's so freaking hot!"
"Yeah, dude, would you tap that?"
"I don't know man, I heard the entire football team did..so that's a pretty questionable vajayjay."