IPA: /ˈaɪd.ləs/
KK: /ˈaɪdlnəs/
The condition of not being active or doing anything; a time when someone is not working or is being lazy.
His idleness during the summer led to boredom and a lack of motivation.
Idleness is formed from "idle" (from Old English *idel*, meaning empty or vain) and the suffix "-ness" (meaning the state or quality of). The word "idleness" refers to the state of being idle or inactive.
Think of the word 'idle' meaning empty or doing nothing, and remember that 'idleness' is the state of being inactive.