dumblessly 

When you forget what to say during your presentation and start bullshitting words

Sometimes we walk around dumblessly, not knowing whats happening

dumblessly by simysimsim June 12, 2014

dumbless 

It’s just dumbless....

That’s a dumbless decision...

dumbless by Thatword84 September 14, 2019

dumbassly 

adverb. in a way that really makes you think, dude. that was a really idiotic way of doing something.

bro, did you really have to do that so dumbassly?
what?
you poured the milk before the cereal, dumbassly.

dumbassly by theguy_spykids3 December 27, 2017