Collocations for undone - adj.

slightly

be
come
My button's come undone again.

leave sth
He was wearing a white shirt with the first few buttons left undone.

get sth
I can't get this knot undone.

be
remain
leave sth
We left the cleaning undone and went out for the day.

Undone is used with these nouns:
collar, shoelace, tie