Possible Clues:

• Gets the tide out, by the sound of it
• Undoes, loosens a knot
• A loosens like this to a relative extent
• Frees mum's sisters from a slow start
• Sets loose
• Makes a knot not a knot
• Loosens, as a 35 Down
• Lets free
• Frees from a knot
• Releases United fixtures after noon