Undertaining 

Not entertaining. Boring. Not interesting. mind-numbing, tiresome, And dull.

That guy Brian is sooo undertaining.

Undertaining by BryGasm March 9, 2010

undermining 

The act of under estimating something about someone or the act of making a person feel inferior to ur to your list of skills

You are undermining my knowledge bro

undermining by La SAPE August 18, 2019

untertaining 

–adjective

Unamusing; not entertaining.

As expected, my latest attempt at online dating was profoundly untertaining. Internyet!

untertaining by miamac March 14, 2010

Undertaking 

The beggining of a dangerous task,or venture.

Climbing that mountain was a very difficult undertaking.

Undertaking by BlackPohatu October 4, 2016