'Toy Bass' doesn't really grab my ear, and 'Double Bass' or 'URB' or some of the other names don't seem to convey the right grandeur for the big fiddle. This brings me to this proposal: The Bass (with capitalization) for, well, The Bass. The Slab for electric. Or, to borrow from some older players, simply call it 'Fender Bass' -- that should get a few Slabbists in a huff. ...and EURB? How about The Mullet?
I'm partial to the noted Texan philospher Billy Gibbons' turn of the phrase: "Gonna spank THE PLANK.". It seems to convey the full majesty of the occasion . . .
Many years ago, long before the dawn of talkbass, some cats were hangin' talkin' 'bout sheddin' and thus were coined the official names of the two instruments to which talkbass was later dedicated: toybass, realbass. I don't think there's much mere mortals like us can do to change that now.