The definition of sloth would be laziness, unwillingness to work or act.
Two context clues are the word "idleness" and the phrase "doing of nothing". Idleness may mean boredom, but also dullness. Doing of nothing clearly supports the notion of not working, not acting.
I wrote one but it won’t let me type it because it’s apparently not the ‘right answer’
“Was” is the helping verb
“Taking” is the main verb