IPA: /ˈʃɪftləsli/
KK: /ˈʃɪftlɪsli/
In a way that shows a lack of ambition or energy; doing things without effort or purpose.
He approached his work shiftlessly, never putting in the effort to succeed.
Shiftlessly → It is formed from "shift" (from Old English "sciftan", meaning to arrange or move) and "-less" (meaning without). The word "shiftlessly" describes a state of being without the ability or inclination to move or act effectively.
Think of someone who is 'without' ('-less') the ability to 'move' or 'arrange' ('shift') things effectively — that's why shiftlessly means lacking energy or purpose.