1) Bit of unfinished business 2) Detail to tie up 3) Something to tie up 4) Unresolved detail 5) Unresolved thing 6) Unsettled detail Found on https://www.crosswordclues.com/clue/loose-end
a part or piece left hanging, unattached, or unused: Remind me to tack down that loose end on the stairway carpet. · an unsettled detail, as of a business matter: The arrangements have been made, except for a few loose ends. · in an uncertain or unsettled situation or position: Ever since leaving the company, he's been at loose ends... Found on https://www.infoplease.com/dictionary/loose-end