That's the vita/PS4/PS3 part sorted, look at the definition of handheld I linked you earlier Wii U doesn't fall under that as you're rooted to one singular location your home while a handheld by definition allows gaming everywhere so by that definition Wii U is not a handheld much like the same way a cordless house phone is not a mobile phone as a result Wii U is not a hybrid.
A Handheld is any gaming device you hold in your hands. The range/distance you can take it is not what the term "handheld" entails.
So yes, the WiiU is a handheld. It's also a fixed console. Thus a hybrid.
If we want to go broad on the definition it doesn't have to be a gaming device or even an electronic device. A hammer is a handheld, a book is a handheld, a screwdriver is a handheld, a knife is a handheld. A Swiss Army Knife is a hybrid, a book with a sturdy cover (sturdy enough to use it for hammering) could also be a hybrid
"Console" is also a broad term and includes non-gaming devices and even non-physical stuff like command-line interfaces.
But we are in a gaming forum and if there is talk about "handhelds", usually we are talking about "hand-held dedicated gaming consoles". And if there is talk about "consoles", usually we are talking about "dedicated gaming consoles connected to a TV".
Of course if we are talking here about a console hybrid, we mean a hybrid of a "hand-held dedicated gaming console" and a "dedicated gaming console connected to a TV". Not of a hybrid between a "hand-held dedicated gaming console"and something other or a hybrid between a "dedicated gaming console connected to a TV" and something other. You keep ignoring that.