lame
 

what's the most lamest word in the dictionary?
and what word is most disapointing (sounds like a good thing, but is really a bad thing) in the dictionary?

'grammar'.

"Dictionary". If you have the thing right in front of you you don't need to look it up to know what it is.

"Disappointing", because nothing is more disappointing than "disappointing".

'Incorrectly', because it's spelled incorrectly. :p That was pretty damn lame.