I came across the word "wifty" in my reading. The book takes place in the 60s, and this particular part was in Haight Ashbury in San Francisco where they were using a lot of drug slang. I couldn't find it in the online slang dictionaries, though I did come across it on a word board that I have never seen before. It apparently means undependable. The discussion on the board (mind you, it was all conjecture) went like this: "I hear 'wiff.' 'Take a wiff of this, will ya.' The word (not in the dictionary, by the way) conjures up something which is ephemeral (lasting a very short time; transitory) which is, naturally, something not dependable."
I don't recall ever hearing wifty before, but M-W has. It seems unrelated to wiff in "take a wiff of this, will ya". That wiff is actually whiff (again, is the h silent or not?), which I associate with smell (M-H, 1 b), as in "take a whiff of that perfume".
Thanks, Tinman. I couldn't find it in dictionary.com, and then I tried the online slang dictionaries. I should have tried onelook!
Still, I find ditsy to be a bit different from undependable.
I am wondering if it was a 60s word. Some of the other words (from Haight Ashbury) that it was used with were: zonked, zapped, hopped up, and wigged out.