The correct answer was, in fact, G: a dream or vision. According to m-w.com its etymology is Middle English, from Old English swefn sleep, dream, vision.

Faldage and rodward both guessed the correct answer, with Faldage picking up one point and rodward getting two.

The bluff with the most votes was the "joint" submittal from tsuwm and Bingley (their guesses were so similar that I only included one). They each get a whopping four points, since one of the votes was tsuwm's red herring. Three people cast a vote for wordcrazy's metallurgical bluff, and the two votes for paulb's seesaw definition balance each other nicely.

Here are the updated scores:

tsuwm......................10+4=14
Sparteye...................11
Bingley.................... 6+4=10
Geoff........................10
wordcrazy.................5+3=8
paulb........................5+2=7
rodward.....................4+2=6
Flatlander..................6
Rapunzel...................4
Bridget96...................4
Jazzoctopus..............4
wwh..........................3
fiberbabe....................3
RhubarbCommando.....3
jimthedog....................2
WhitmanO’Neill...........2
maverick.....................2
Faldage......................1
freckled_snout.............1
Jackie........................1

Definitions for maffle will be posted later today.

*** CORRECTION ***

A couple of points regarding the scoring of the last round have occurred to me:
1. The tsuwm/Bingley bluff actually® received 5 votes, with one of them being tsuwm's red herring guess, so the two of them will get 4 points each, not 6.

2. I should note that the wording of the definition was tsuwm's, but Bingley's was so similar ("This is an alternative form of swive, a rather vulgar word meaning fornicate") that I just went with tsuwm's wording because he submitted it first.

Corrected scores can be found above in red. Thank you for your understanding.