fundertaking 

undertaking something that is fun

I am fundertaking to build a tree house.
Could be used with sarcasm.

fundertaking by Steel magnolia February 13, 2013

Undertaking 

The beggining of a dangerous task,or venture.

Climbing that mountain was a very difficult undertaking.

Undertaking by BlackPohatu October 4, 2016

Fundertainment

to be fun and Entertaining at the same time. While being the same thing, People had to make a new word for it to make it sound cool.

Chuck Norris is Fundertainment

Fundertainment by RoadkillJoe July 7, 2009